001 COVER EWAP Mar13 VER 1 No9 - APACRSaspx.apacrs.org/apacrs-publication/pdf/Binder Asia Pacific Vol9No1... · Just simply correcting the spherical refractive ... view astigmatism

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APACRS meeting highlights — P. 5, 7, 31Surgical blades — P. 51 OVD cheat sheet — P. 53

Table of Contents P. 4 & P. 6

Feature: Astigmatism

Getting the cornea

into shape — Page 8

Management of

corneal astigmatism — Page 12

Experts on astigmatism

correction — Page 15

Impact of posterior

corneal astigmatism — Page 17

Meeting reporterThe 28th APAO

Congress — Page 55

Vol.9 No.1

March 2013 The Asia-Pacifi c Association of Cataract and Refractive Surgeons

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3EWAPMarch 2013 3

Letter from the Guest EditorDear Friends

Cataract surgeons are now, more than ever, aware that preexisting corneal astigmatism needs to be corrected in

order for patients to gain the full visual benefi ts of cataract surgery, especially in those having multifocal or

accommodating intraocular lenses implanted. Just simply correcting the spherical refractive error without

addressing the corneal astigmatism will not deliver the optimal results that our cataract patients demand today. How

many of us at present, as cataract surgeons would be satisfi ed that an unaided vision of 6/12 or 6/9 due to residual

astigmatism is considered a surgical success? I would say none. Our patients would also agree.

Astigmatism has always been diffi cult to treat. Following presbyopia, which remains the most enigmatic and diffi cult refractive error to correct,

astigmatism is the most diffi cult refractive error to treat. This is because astigmatism not only has a magnitude, it also has an axis (direction). It is a vector.

In order to treat astigmatism fully, one has to not only correct the magnitude but also take into account the axis of the astigmatism. In the human eye,

measurements of the magnitude and axis of astigmatism have reached high levels of accuracy and reproducibility, but the treatment of it can be confounded

by issues of visual fi xation and cyclotorsion of the eye from the usual measurement position (seated) to the usual treatment position (reclined) of the patient.

In this issue, we have several excellent articles on the measurement and treatment of astigmatism in cataract patients. There have been huge improvements

in the way we measure astigmatism which have progressed beyond the manual keratometer to multipoint Placido, Scheimpfl ug and wavefront-based

techniques that deliver outstanding accuracy and precision. Intraoperative methods of astigmatism correction have also progressed in leaps and bounds

with limbal relaxing incisions, femtosecond laser arcuate keratotomy and toric IOLs being the preferred methods of intraoperative correction today.

One article of particular signifi cance is on the work of Douglas Koch, MD, and Li Wang, MD, on the role that posterior corneal astigmatism plays in the

surgical management of astigmatism. It provides a lot of illumination on how we should think of the cornea as a structure that has not only a front surface

that we can surgically manipulate, but also a posterior surface that affects the results of our treatment that we cannot manipulate as yet. To me, it does

explain why sometimes we do not get the surgical outcome expected when treating low levels of corneal astigmatism in cataract patients with a toric IOL. I

strongly recommend that interested colleagues read the full paper in the Journal of Cataract & Refractive Surgery referenced in the article. It will change how

you use toric IOLs.

It would appear that we as clinicians and surgeons view astigmatism as an always debilitating optical aberration that must be relentlessly pursued and

corrected to oblivion. Is this always true? I do not think so. I feel that there is a role for small magnitudes of corneal astigmatism in the appropriate axis

that might provide the eye with an IOL an increased depth of fi eld without signifi cant visual degradation and loss of contrast sensitivity. We all remember

cases of patients with pseudoaccommodation demonstrating excellent vision for distance and near before the days of multifocal and accommodating IOLs.

Perhaps we should not always view astigmatism as an evil refractive error. We could harness it to the benefi t of our patients. Food for thought and after

dinner conversation with our colleagues!

Finally, we have several comments from our Asia-Pacifi c surgeons on some of these articles. This gives a very special and unique perspective that is the

hallmark of our publication and I am sure readers will fi nd this edition informative and benefi cial to their clinical practice.

I wish all of our readers and supporters the very best for 2013.

Warmest regards

Chan Wing Kwong, MDGuest Medical Editor and Editorial Board Member, EyeWorld Asia-Pacifi c

EYEWORLD ASIA-PACIFIC EDITORIAL BOARD

CHIEF MEDICAL EDITORGraham BARRETT, Australia

MEMBERS

Abhay VASAVADA, India

ANG Chong Lye, Singapore

CHAN Wing Kwong, Singapore

CHEE Soon Phaik, Singapore

Choun-Ki JOO, Korea

Hiroko BISSEN-MIYAJIMA, Japan

ASIA-PACIFIC CHINA EDITION

Editors-in-ChiefZHAO Jialiang

ZHAO Kan Xing

Deputy EditorHE Shouzhi

Assistant EditorZHOU Qi

ASIA-PACIFIC INDIA EDITION

Regional Managing EditorS. NATARAJAN

ASIA-PACIFIC KOREA EDITION

Regional Editor-in-ChiefHungwon TCHAH

Regional Managing EditorChul Young CHOI

Hungwon TCHAH, Korea

John CHANG, Hong Kong

Johan HUTAURUK, Indonesia

Kimiya SHIMIZU, Japan

Pannet PANGPUTHIPONG, Thailand

Prin ROJANAPONGPUN, Thailand

Ronald YEOH, Singapore

S. NATARAJAN, India

YAO Ke, China

YC LEE, Malaysia

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March 20134 EWAP TABLE OF CONTENTS

Feature March 2013Astigmatism 8 - 18

Letter from the Guest Editor 3

30

Getting astigmatic cataract patients into corneal shape 8Beefi ng up your astigmatic measurement and treatment routineby Maxine Lipner

Modalities for correcting total corneal astigmatism 12With several now available, surgeons weigh in on the pros and cons of eachby Michelle Dalton

Experts differ on corneal astigmatism correction in cataract surgery 15Total corneal astigmatism correction during cataract surgery could be either by eliminating it or by leaving slight with-the-rule astigmatismby Erin L. Boyle

Posterior corneal astigmatism vital to calculating correct total astigmatism 17Researchers highlight the signifi cance of posterior corneal astigmatism in estimating total corneal astigmatismby Erin L. Boyle

CATARACT/IOL

A new complication after endothelial keratoplasty procedures 19 Opacifi cation, calcifi cation linked to a certain type of IOL materialby Vanessa Caceres

REFRACTIVE

Mysterious infection after LASIK has lessons for all 33A recent case in the Middle East highlighting the need for refractive surgeons to be aware of serious corneal problemsby Matt Young

19

33

38

44

Preventing the Argentinian Flag Sign: Phaco capsulotomy 22 An overview of the phaco capsulotomy technique for preventing complications with white and intumescent cataractsby Christopher C. Teng, MD

Taking the spin out of toric rotation: Part 1 25 A two-part case-based examination of toric IOL rotationby Steven G. Safran, MD

Taking the spin out of toric rotation: Part 2 28 by Steven G. Safran, MD

The business side of femto for cataract 30How to integrate a femtosecond laser into your practice, and when to use itby Michelle Dalton

Presbyond Laser Blended Vision: Another approach to presbyopia 34A laser-based approach that takes advantage of natural mechanisms within the optical systemby Dan Z. Reinstein, MD

A scleral approach to presbyopia 38Procedure in phase III U.S. FDA trial targets plano presbyopesby Vanessa Caceres

Strengthening corneas in Singapore 40Surgeon explains why and how he performs crosslinking during many LASIK proceduresby Matt Young

CORNEA

Cornea surgeons compare thin DSAEK and DMEK as options for endothelial keratoplasty procedures 44 Looking beyond the obviousby Ellen Stodola

Expanding corneal tissue availability 47 Largest cornea clinical trial today compares preservation timeby Vanessa Caceres

DMEK gaining ground on


5

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March 20136 EWAP TABLE OF CONTENTS

APACRS Secretariat11 Third Hospital Avenue, Singapore 168751

Fax: (65) 6327 8630 Email: [email protected]: www.apacrs.org

50 51

51

GLAUCOMA

Can diet influence the risk of glaucoma? 49Studies highlight the relationship between diet and glaucomaby Tony Realini, MD

New technology could improve eye drop delivery 50New delivery system seeks to address need for more effective administration of medicationby Ellen Stodola

DEVICES

Not all blades serve all purposes 51When it comes to choosing instrumentation to make incisions, variables between disposable and reusable blades make a differenceby Michelle Dalton

PHARMA FOCUS

Experts provide OVD cheat sheet 53 Rigging the game to win in challenging cataract casesby Maxine Lipner

NEWS & OPINION

Meeting Reporter 55 Reporting live from the 28th APAO-AIOS Congress

56

55

P U B L I S H I N G S TA F F

Publisher APACRSCharity Wai [email protected]

Donald R. Long

[email protected]

APACRS EditorialKathy [email protected]

Summer [email protected]

Christine ShimmonSenior Staff WriterChiles Aedam R. Samaniego

ASCRS Editorial

EditorJena Passut

Managing EditorStacy Majewics

Senior Staff WriterErin Boyle

Staff WriterEllen Stodola

ProductionGraphic DesignerJulio Guerrero

Production AssistantDaniela Galeano

Contributing EditorsVanessa Caceres – Lakeland, Florida

Michelle Dalton – Reading, Pennsylvania

Rich Daly – Arlington, Virginia

March 2013 Volume 9 • No.1

Enette Ngoei – Singapore

Matt Young – Malaysia

Senior Contributing EditorMaxine Lipner – Nyack, New York

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APACRS Publisher: EyeWorld Asia-Pacifi c Edition (ISSN 1793-1835) is published quarterly by the Asia-Pacifi c Association of Cataract & Refractive Surgeons (APACRS), c/o Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, telephone (65) 6322-7469, fax (65) 6327-8630, email [email protected]. Printed in Singapore.

EyeWorld Asia-Pacifi c Chinese Edition (ISSN 1521-7566) is jointly published quarterly by the Asia-Pacifi c Association of Cataract & Refractive Surgeons (APACRS), c/o Singapore National Eye Centre, 11 Third Hospital Avenue, Singapore 168751, telephone (65) 6322-7469, fax (65) 6327-8630, email [email protected]; and the Chinese Ophthalmological Society (COS), c/o Chinese Medical Association, 42 Dongsi Xidajie, Beijing 100710, PR China, telephone (86-10) 6524-9989 ext 2456, fax (86-10) 6512-3754. Printed in Beijing, PR China.

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Licensed through the American Society of Cataract & Refractive Surgery (ASCRS), 4000 Legato Road, Suite 700, Fairfax, VA 22033-4003, USA. All rights reserved. No part of this publication may be reproduced without written permission from the publisher. Letters to the editor and other unsolicited material are assumed intended for publication and are subject to editorial review and acceptance. The ideas and opinions expressed in EyeWorld Asia-Pacifi c do not necessarily refl ect those of the editors, publishers or its advertisers.

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KDN number: PPS1766/07/2013(022955) MCI (P) 160/02/2013


March 2013 EWAP TABLE OF CONTENTS 7

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March 20138 EWAP FEATURE

Getting astigmatic cataract patients into corneal shapeby Maxine Lipner Senior EyeWorld Contributing Writer

Beefi ng up your astigmatic measurement and treatment routine

While for decades

practitioners neglected

residual astigmatism

when removing

cataracts, many wouldn’t dream

of it now, according to Stephen

S. Lane, MD, adjunct professor

of ophthalmology, University of

Minnesota, Minneapolis, Minn.,

USA. “The way that I look at

astigmatism in cataract surgery

is the same way I’ve looked at

it my entire career: You would

never want to give patients glasses

without the astigmatism correction

in the glasses,” Dr. Lane said. “So

why with cataract surgery would

we essentially ignore astigmatism

and just treat the spherical

correction?”

Evolving equipmentPractitioners today have

their pick of equipment for

measuring astigmatism. Jack T.

Holladay, MD, clinical professor

of ophthalmology, Baylor College

of Medicine, Houston, Texas, USA,

noted that technology to measure

astigmatism has been evolving

for years, beginning with original

manual keratometers. “Those

devices used a circle and measured

the principal meridians of the

refl ected image,” Dr. Holladay

said. “If the refl ected image was

an oval that meant that you had

astigmatism.” With this method,

usually four points, located

about 3.2 mm apart, were used to

measure the principal radii.

As automated keratometers

emerged, the size of the ring

was reduced, changing the area

that was actually measured.

Since the magnitude and axis of

astigmatism is not always constant

as one moves peripherally from

the center, signifi cant differences

would result. Even today, the

IOLMaster (Carl Zeiss Meditec,

Jena, Germany) measures points

that are 2.5 mm apart on a 44 D

cornea, while the Lenstar (Haag-

Streit, Mason, Ohio, USA) measures

two rings, one with points 1.65

mm apart and the other with

points 2.35 mm apart, and arrives

at an average of the two.

Meanwhile, topographers

would measure a zone from 1-9

mm in diameter. They would

measure thousands of points

within this zone. “That’s when we

began to fi nd with topography that

as you moved out from the center

of the cornea, the magnitude

and axis of astigmatism was not

constant on many patients,” Dr.

Holladay said.

The development of

tomographers, beginning with

the Orbscan (Bausch + Lomb,

Rochester, NY, USA), the Pentacam

(Oculus, Lynwood, Wash., USA),

and Galilei (Ziemer Ophthalmic

Systems, Port, Switzerland), would

allow practitioners to measure

both surfaces and the thickness

over a 9 mm area, including the

center. These would measure

all of the points within a zone

and determine the best fi t to the

surfaces using a sophisticated

algorithm. Dr. Holladay said

measuring all of these points

on both surfaces increases the

accuracy, particularly when

corneal irregularity is present.

Taking the back surface into

account also improves accuracy.

“What we’re fi nding today when

we begin to correct astigmatism

with toric IOLs is that assuming

that the back surface astigmatism

is a constant fraction of the front

surface is not always true,” Dr.

Holladay said. A recent study by

Douglas Koch, MD, showed that

the back surface is becoming

signifi cant at the level of about ¼

or ½ a diopter in terms of fi ne-

tuning the total astigmatism of the

cornea, he said.

Another group of devices,

intraoperative wavefront

aberrometers such as the ORA

(WaveTec, Aliso Viejo, Calif., USA)

and Clarity (Holos, Pleasanton,

Calif., USA), now allow surgeons

to directly take refractive

measurements at the time of

surgery. Since they use the cornea

as a lens when measuring the

refraction, they automatically

take into account both surfaces

and any irregularities. This is

also something Dr. Holladay sees

as enhancing accuracy. “You’re

actually sending light through

the cornea alone (for the aphakic

measurement), through the cornea

and IOL for the pseudophakic

measurement, bouncing it off the

retina, and having it come back

like a refraction,” he said. This

technique is more accurate than

measuring individual curvatures

and indices of refraction and

trying to calculate the sphere and

cylinder.

However, when the

intraoperative measurements

determine that the

spheroequivalent power or toricity

of the IOL is different than the

values predicted pre-op, the

surgeon must bracket the IOL

power and toricity, which may

require bringing 9 IOLs (three

SEQ powers and three toricities

for each SEQ power), Dr. Holladay

explained. Nevertheless, this is

better than waiting until surgery

and fi nding that the optimal

IOL is unavailable and not in

the inventory. Also, surgeons are

reimbursed for pre-op biometry

and would not abandon these

measurements with all of the

cutbacks until there are payments

for intraoperative measurements

that are completely up-charged to

the patient.

AT A GLANCE• Different devices consider

varying numbers of points

on the cornea in determining

astigmatism.

• The posterior surface is

becoming signifi cant in fi ne-

tuning corneal astigmatism

following cataract surgery.

• In reconciling confl icting

measurements, practitioners

herald different approaches.

Report from the Pentacam, which can measure the shape of the cornea and astigmatic regularity and magnitude

Source: Jack T. Holladay, MD

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March 2013 9EWAP FEATURE

a

y

Views from Asia-Pacifi cArup CHAKRABARTI, MDSenior Consultant, Cataract and Glaucoma Services, Chakrabarti Eye Care CentreNo. 102, Kochulloor, Trivandrum 695011, Kerala, IndiaTel. no. +91-471-2555530Fax no. [email protected]

In this era of refractive cataract surgery, our goal is to reduce the patient’s dependence on glasses in the postoperative period, if not eliminate it altogether. This has come about due to our ability to more accurately

determine IOL power (Optical Biometry: IOLMaster and Lenstar) and to the incorporation of steps to reduce the quantum of postoperative astigmatism. Accurate determination of the preoperative astigmatism, knowledge of the SIA and an appropriate astigmatism reduction strategy play an important role. Preoperative astigmatism is traditionally measured using: 1. Manual keratometry, 2. Automated keratometry, 3. Corneal topography, 4. Optical Biometry. In an ideal situation the K-readings from all the devices will give similar readings, which, unfortunately, is hardly ever the case because devices don’t always measure the same areas of the cornea.

The various methods to reduce postoperative astigmatism in cataract patients have been limbal relaxing incisions, paired opposite clear corneal incisions, toric IOLs and laser. However, toric IOLs have been increasing in popularity for various reasons. Satisfactory results with these lenses require proper work up of preoperative astigmatism, a good surgical technique and proper IOL handling/alignment. Toric IOLs are not used in patients with irregular astigmatism. Topography is a tool that may detect astigmatic irregularity which may go undetected in conventional keratometry. In case of major disagreement between the various devices it may be a good idea to perhaps not employ a toric IOL after proper explanations to the patient. In case of a minor disagreement, the axis of the astigmatism may be assessed using manual or automated keratometry and the actual magnitude may be taken from topography according to Dr Lane. Some surgeons would like to average the measurements after repeating them to ensure consistency in the values for each device. These devices don’t put due importance to the back surface of the cornea. Dr. Douglas Koch has shown in his recent study that the corneal back surface plays a signifi cant role in terms of “fi ne-tuning the total astigmatism of the corneas”. The back surface is taken into account by tomographers, e.g. Orbscan (Bausch + Lomb), Pentacam (Oculus) and Galilei (Ziemer). These limitations may perhaps be answered by a group of devices—intraoperative wavefront aberrometers such as the ORA (Wavetec) or Clarity (Holos)—which allow surgeons to directly detect accurate refraction including astigmatism at the time of surgery after the cataract is removed. However, the surgeon should be ready with a wider inventory of toric IOLs in case the intraoperative measurements differ from the predicted preoperative values.

The surgeon should also have a clear idea of his SIA and the various factors impacting it to optimize his astigmatic outcomes. Neglect of this component often leads to suboptimal results with toric IOLs.

Intraoperative lens positioning along the proper axis is of paramount importance. The standard technique of marking with ink is considered to be inadequate. The emerging guidance systems play an increasingly important role for proper intraoperative lens placement.Guidance devices such as the SMI (Alcon, Fort Worth, Texas, USA/Hünenberg, Switzerland) take a photograph of the eye and match this intraoperatively so that landmarks are identifi ed, ensuring proper lens positioning.

The bottomline is no single device currently serves all functions with regard to corneal measurements and many believe that intraoperative aberrometry will become the standard of care in the future enabling practitioners to better achieve the target of emmetropia without astigmatism and possibly other higher aberrations such as spherical aberration and coma.

Editors’ note: Dr. Chakrabarti is a consultant for Allergan (Irvine, Calif., USA) but has no fi nancial interests related to his comments.

How devices measure upHow devices measure up

Practitioners today are fortunate to have a variety of devices for measuring astigmatism at the ready. Here’s what’s available:

Manual keratometry determines the quantity of astigmatism and the axis, according to Dr. Trattler. “It’s good for planning cataract surgery, but it doesn’t help us to fi gure out whether the cornea is regular or irregular,” he said.

The IOLMaster considers corneal shape, using three measurements for astigmatism. “It’s a very rudimentary method, but it’s very accurate as far as helping us plan for the right intraocular lens power,” Dr. Trattler said. This will tell if astigmatism is present, how steep the cornea is, and help with surgical planning but will not identify irregular astigmatism.

Corneal topography uses imaging technology to get a sense of the magnitude of the astigmatism and the shape of the cornea, Dr. Trattler explained. It can tell if the cornea is regular or irregular and if the patient has a condition such as keratoconus.

The Pentacam measures the shape of the cornea and the magnitude and regularity of the astigmatism. “You press it back and can determine the shape of the cornea and if there’s any regularity or irregularity,” Dr. Trattler said.

The Galilei gives measurements for both anterior and posterior corneal curvatures. This can be helpful in considering what posterior astigmatism contributes, which has gained importance thanks to Dr. Koch’s new nomogram for implanting toric IOLs, which uses both measurements, Dr. Trattler explained.

The Clarity and the ORA offer intraoperative wavefront measurements of astigmatism. These allow practitioners during surgery to measure the cornea through the power of the astigmatism. “It helps you to fi ne-tune your planning,” Dr. Trattler said.

Devices such as the iDesign (Abbott Medical Optics, AMO, Santa Ana, Calif., USA), the iTrace (Tracey Technologies, Houston, Texas, USA), and the OPD (Marco, Jacksonville, Fla., USA) can analyze a combination of topography and wavefront measurements at the same time. These units can give corneal shape and also determine whether the astigmatism is symmetrical or asymmetrical.

Optimizing outcomesHow can practitioners best

use devices to optimize results for

astigmatic cataract patients?

Dr. Lane stressed that

it’s important to begin by

distinguishing lenticular from

corneal astigmatism. “Obviously

the astigmatism associated with

the lens will be absent following

the removal of the cataract,” he

said. “So you need to have an idea

of what the post-operative corneal

astigmatism will be.”

He fi nds that’s best

accomplished pre-op with the aid

of different available tools. “Some

of them are automated like the

measurements that you would

take with an IOLMaster or with

the Lenstar,” he said. “Some of

them have been around for many

decades like manual keratometry,

and some of them are looked at

in terms of corneal topography or

even OCT.”

Intraoperatively, Dr. Lane sees

systems such as the ORA and the

Holos as serving an important

function. “With the WaveTec

aberrometry and in the future with

Clarity aberrometry, that will help

us to determine what the amount

of astigmatism is after we’ve

removed the cataract on the table,

real-time,” he said.

He also stressed the importance

of using a guidance system

for proper intraoperative lens

placement. “We have guidance

systems because with astigmatism

not only is there an amount,

there’s also a direction,” he said.

“So you can choose the correct

power implant, but if you put it

in the wrong position you’ll be

inaccurate in your correction of

the astigmatism.” Guidance devices

such as the SMI (Alcon, Fort

Worth, Texas, USA/Hünenberg,

Switzerland) take a photograph

of the eye and match this

continued on page 10


10 March 2013EWAP FEATURE

Views from Asia-Pacifi cTim ROBERTS, MBBS, MMed, FRANZCO, FRACSConsultant Ophthalmologist and Clinical Senior Lecturer, Department of Ophthalmology, Royal North Shore Hospital, University of SydneyConsultant Eye Surgeon, Vision Eye InstituteLevel 3 270 Victoria Ave, Chatswood,Sydney, Australia 2067 Tel. no. +61-2-9424-9999Fax no. +61-2-9415-4220 [email protected]

After myopia and hypermetropia, astigmatism remains the major optical aberration causing reduced vision. A signifi cant number of patients presenting for cataract surgery have coexisting astigmatism, which if left uncorrected, is likely to result in reduced postoperative visual quality.1 Assessing cataract surgery success by only looking at best-corrected

visual acuity or spherical equivalent targets will result in suboptimal refractive outcomes and dissatisfi ed patients. Improvements in cataract surgery and intraocular lenses (IOLs), combined with a generational change in patient expectations, have resulted in a paradigm shift with spectacle independence now regarded by most ophthalmologists and patients as the expected and desired outcome following surgery.

Accurately measuring preoperative keratometric cylinder and planning for spherical and astigmatic emmetropia should be the target for all patients when removing cataracts. Various techniques have been used in combination with non-toric IOLs to reduce or eliminate astigmatism; however, these techniques have been limited by induced higher-order aberrations, the amount of astigmatism that can be treated and the long-term mechanical stability of the cornea following relaxing incisions. Options to treat astigmatism include incision placement on the steep corneal meridian, paired opposite clear corneal incisions, corneal relaxing incisions and laser refractive surgery.

The availability of toric IOLs based on widely used non-toric IOL platforms, combined with improved rotational stability, has made toric IOLs a viable option for many surgeons. They produce accurate and predictable refractive results and do not require additional expensive instrumentation or special surgical skills and training.

The construction of a circular, consistently-sized capsulorhexis which overlaps the IOL throughout 360° is important in maximizing IOL stability and reducing the onset of posterior capsular opacifi cation.2 The recent introduction of femtosecond lasers to cataract surgery has shown promising results with reports of greater precision and accuracy of the anterior capsulotomy and more stable and predictable positioning of the intraocular lens.3,4,5 The FS laser can also create extremely accurate corneal incisions for both the main wound and astigmatic relaxing incisions in the steep corneal meridian.

Key factors in achieving successful results with toric IOLs are thorough education of offi ce, anesthetic and nursing staff, proper patient selection, accurate measurement of corneal cylinder, and accurate IOL alignment intraoperatively. The cardinal meridians are marked on the cornea with the patient in the upright position prior to commencing surgery. These reference marks can be made with commercial instruments or by the surgeon aligning the horizontal meridian with the horizon. Correct alignment of the toric IOL axis can be confi rmed under the operating microscope by using a fi xation ring (Mendez marker, Mastel Inc., Rapid City, SD, USA) after wound hydration and reformation of the anterior chamber.

Key Points• After myopia and hypermetropia, astigmatism remains the major optical aberration causing reduced vision• A signifi cant number of patients presenting for cataract surgery have coexisting astigmatism, which if left uncorrected, is likely to result in reduced postoperative visual quality• Best-corrected visual acuity and spherical equivalent refraction should not be used as indicators of good refractive outcomes• Calculations should not be based on the subjective refraction as progressive lenticular astigmatism may either mask corneal astigmatism or give a falsely high estimate of cylinder• Manual and automated keratometry measurements are reliable with comparable results• Topography should be performed if astigmatism >1.5 D to exclude corneal pathology

References

1. Ferrer-Blasco T, Montés-Micó R, Peixoto-de-Matos SC, Gonzá-les-Méijome JM, Cerviño A. prevalence of corneal astigmatism before cataract surgery. J Cataract Refract Surg. 2009;35:70-75.2. Ravalico G, Tognetto D, Palomba M, et al. Capsulorhexis size and posterior capsule opacifi cation. J Cataract Refract Surg. 1996;22:98-103.3. Kránitz K, Miháltz K, Sándor GL, et al. Intraocular lens tilt and decentration measured By Scheimpfl ug camera following manual or femtosecond laser-created continuous circular capsulotomy. J Refract Surg. 2012;28:259-63.4. Roberts TV, Lawless M, Chan CC, et al. Femtosecond laser cataract surgery: technology and clinical practice. Clin Experiment Ophthalmol. 2012 Jul 12. doi: 10.1111/j.1442-9071.2012.02851.x. [Epub ahead of print]5. Kránitz K, Takacs A, Miháltz K, et al. Femtosecond laser capsulotomy and manual continuous curvilinear capsulorrhexis parameters and their effects on intraocular lens centration. J Refract Surg. 2011;27:558-63.Editors’ note: Dr. Hwang and Prof. Joo have no fi nancial interests related to their comments.

Editors’ note: Dr. Roberts has no fi nancial interests related to his comments.

intraoperatively so that landmarks

are identifi ed, ensuring proper lens

positioning.

Meanwhile, William B. Trattler, MD, director, Cornea,

Center for Excellence in Eye Care,

Miami, Fla., USA, emphasized

the need for topography on all

astigmatic patients. “You need a

topography because you can be

surprised if the astigmatism is

quite irregular,” he said. “It could

be keratoconus or it could be other

irregularities, and unless you use

the topography, you’ll have no

idea.”

This could lead to trouble

in a case in which, for example,

the IOLMaster identifi es 1 D of

astigmatism. If the practitioner

assumes that this is regular and

implants a toric lens, if it turns

out to be irregular that will make

things worse, Dr. Trattler warned.

He uses the IOLMaster on every

patient to help measure the axial

length and determine the right

intraocular lens power, pairing

this with Placido disk topography.

In unusual cases he also employs

the Pentacam, which measures the

shape of the cornea. “They’re very

complementary and can be helpful

in fi guring things out,” Dr. Trattler

said.

Dr. Holladay stressed that

no single device currently serves

all functions. “The topography

wavefront devices don’t measure

the back surface or the thickness

of the cornea, and the tomography

devices measure the front and

the back surface of the cornea but

don’t measure the wavefront,”

he said. “So you don’t get

everything from any one of

them.” What is needed, he thinks,

is a tomographer that measures

wavefront.With no single device available,

this may mean reconciling confl icting measurements. In cases of discrepancies, Dr. Trattler recommended averaging measurements or repeating the tests. Dr. Lane advised trusting your own experience. He pointed out that while manual keratotomy remains the gold standard, accuracy somewhat depends on operator experience. However, with

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Getting - from page 9


11March 2013 EWAP FEATURE

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automated keratometry, there’s

often greater ability to duplicate

results. For looking at the direction

of the astigmatism, however,

topography tends to be best. “If

there is a lot of disagreement

typically what I’ll do is use

automated or manual keratometry

to determine magnitude and then

use the topography to look at the

direction of the cylinder,” he said.

Going forward, Dr. Holladay

believes that intraoperative

aberrometry will become the

standard of care in the future

enabling practitioners to better

achieve the target of emmetropia

without astigmatism and possibly

other higher aberrations such

as spherical aberration and

coma. Ultimately this will

enable practitioners to put

patients within 1/8 of a diopter

of spheroequivalent target, the

limit of IOLs available in 0.50

D increments, without any

residual astigmatism or higher-

order aberrations. “When we do

that we’ll have a large number

of patients, more than 70%,

that are much better than 20/20

because the studies show that

approximately 90% of the cataract

age group has the neurological and

retinal function that is as good as

the vision as when they were 19

years old,” he said. EWAP

Editors’ note: Dr. Holladay has

fi nancial interests with Alcon, AMO,

WaveTec, and Oculus. Dr. Lane has

fi nancial interests with Alcon and

WaveTec. Dr. Trattler has fi nancial

interests with AMO and Oculus.

Contact information

Holladay: 713-669-8977, [email protected]: 651-275-3000, [email protected]: 305-598-2020, [email protected]

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Views from Asia-Pacifi cYi LU, MDDirector, Department of Ophthalmology, Eye & ENT Hospital of Fudan University83 Fenyang Road, Shanghai 200031, ChinaTel. no. +86-21-64377134-407Fax no. [email protected]

Nowadays, I agree that attention should be paid to astigmatism correction for cataract surgery in a more comprehensive way, such as taking the posterior surface of the cornea into consideration. Actually, for the

eye as a whole, astigmatism, as a lower-order aberration, has a much greater impact on the visual function than higher-order aberrations such as spherical aberration, so that the correction of spherical aberration should be based on the full correction of astigmatism.

To correct astigmatism accurately, precise measurement is the prerequisite. However, regarding the selection of instruments, there is no gold standard for the evaluation of preoperative astigmatism in cataract patients at this moment. Since each instrument possesses its pros and cons, establishing the optimal measuring approach still requires the support of rigorous randomized controlled trials. And these approaches will constantly be improved in subsequent practice. In fact, if simply considering correcting corneal astigmatism in cataract surgery, Pentacam is better than either the OPDscan or IOLMaster because it measures more corneal points, and it can measure both anterior and posterior corneal surfaces, as well as recognize irregular astigmatism and keratoconus; if both astigmatism and spherical aberration are aimed to be corrected during the surgery, devices that can analyze a combination of topography and wavefront measurements at the same time might be a better choice, such as OPDscan. However, as for those intraoperative measuring equipment mentioned in this article, such as the ORA or Clarity, I am worried that although they can provide timely monitoring of astigmatism, they neglect the importance of surgically induced astigmatism (SIA). If the surgical design is based on these data, one would expect error in the fi nal result due to postoperative corneal incision reconstruction.

Therefore, before the gold standard is established, I suggest that every practitioner evaluate his or her personal SIA precisely, and assess preoperative astigmatism carefully using advanced equipment such as the Pentacam in order to establish a rational surgical plan.

Editors’ note: Dr. Lu has no fi nancial interests related to his comments.


March 201312 EWAP FEATURE

Modalities for correcting total corneal astigmatismby Michelle Dalton EyeWorld Contributing Writer

With several now available, surgeons weigh in on the pros and cons of each

Visually signifi cant

astigmatism (generally

considered 0.50 D or

greater) affects almost

70% of patients presenting for

cataract surgery, and most patients

expect surgeons to correct the

astigmatism along with the

cataract surgery.

Eric D. Donnenfeld, MD,

partner, Ophthalmic Consultants

of Long Island, Rockville Centre,

NY, USA, and clinical professor

of ophthalmology, NYU Medical

School, New York, NY, USA,

believes that even smaller amounts

of astigmatism—perhaps even less

than 0.5 D—can be signifi cant.

Surgeons need to manage and treat

not only pre-op astigmatism, but

surgically induced astigmatism

(SIA) as well, he said.

“The most common mistake

that I see doctors make on

a routine basis in treating

astigmatism is treating the pre-op

astigmatism and not treating the

SIA,” Dr. Donnenfeld said, but

noted there are two websites in

particular that can help surgeons

determine what IOL to use and

what the SIA is (www.acrysoftoric.

com [Alcon, Fort Worth, Texas,

USA/Hünenberg, Switzerland] for

the former and www.lricalculator.

com [Abbott Medical Optics, AMO,

Santa Ana, Calif., USA] for the

latter).

For Louis D. “Skip”

Nichamin, MD, in private

practice, Laurel Eye Clinic,

Brookville, Pa., USA, limbal

relaxing incisions (LRIs) “work

quite well if you treat them

with respect and pay regard

to the surgical technique and

instrumentation used.” If surgeons

measure the patients’ astigmatism

carefully, plan an equally careful

surgery, and execute the LRI with a

“great deal of precision, the results

can be fabulous,” Dr. Nichamin

said. Although there are “defi nitely

studies out there indicating better

results with a toric lens than with

an LRI,” using a premier diamond

blade and paying exquisite

attention to the execution levels

the fi eld with regard to outcomes,

he said.

Incisional techniquesAdvantages of incisional

keratotomy over other methods of

correcting corneal astigmatism are

its lower cost and ease to perform,

said Richard Tipperman, MD,

attending surgeon, Wills Eye

Institute, Philadelphia, Pa., USA.

“But what you’re really after are

predictability, reproducibility,

AT A GLANCE• 70% of patients presenting

with cataract also have

visually signifi cant

astigmatism.

• LRIs can produce exquisite

results, but surgeons need to

execute them with incredible

precision.

• The variable outcomes with

incisional keratotomy may be

unacceptable.

• Femtosecond lasers can

create arcuate incisions so

precise SIA is minimized.

• Toric IOLs remain the “go-to”

choice for higher levels of

astigmatism.

Views from Asia-Pacifi cJohan A. HUTAURUK, MDDirector, Jakarta Eye CenterJl. Cik Ditiro 46, Menteng, Jakarta – 10310 IndonesiaTel. no. +62-21-2922-1000Fax no. [email protected]

Cataract surgery has now become cataract refractive surgery, because the

target is not only visual rehabilitation by removing the cloudy lens but also

to optimize the visual acuity postoperatively, so our patients can expect to

be free of glasses.

Almost 70% of patients presenting with cataract also have astigmatism, this is a

huge number but fortunately, most of them have less than 1.0 D of astigmatism.

Hoffer reported 23% of eyes exhibited more than 1.5 D of astigmatism in a series

of 7500 patients undergoing cataract surgery and others reported that only 8%

exhibited >2.0 D of corneal astigmatism and 2.6% exhibited >3.0 D. Peripheral

corneal relaxing incisions are still the most cost effective modalities to treat

preexisting astigmatism, and the nice thing about this procedure is that we don’t

have to be so accurate but results will almost always reduce the astigmatism. For

example, most patients with <1.0 D astigmatism can be treated by placing the

phacoemulsifi cation on the steep corneal meridian. This is the simplest method

to take advantage of SIA (surgically induced astigmatism) to neutralize the

preexisting astigmatism.

Limbal relaxing incisions (LRI) are the low-cost approach for correction of corneal

astigmatism between 1 and 3 D, but I still prefer to opt for toric IOLs for better

reliability if the patient can afford premium IOLs. Toric IOLs are easier to adopt

since they do not need any additional procedures other than marking the axis and

rotating the toric lens at the end of surgery.

We are aware that the precision of refractive outcome after cataract surgery is

only half compared with LASIK. Only 45% of cataract surgeries are within 0.5 D of

targeted refraction with current biometry compared with 90% in LASIK. Patients

with high corneal astigmatism of >3 D, which is less than 2.5% of the cataract

population, might benefi t from LASIK touch up to reduce the corneal astigmatism

as well as any residual refractive errors.

In my opinion, the best way to correct corneal astigmatism in cataract patients

is to correct the cause of astigmatism, which is in the cornea, rather than to

compensate it with a toric lens. LRI fi ts with this idea and femtosecond laser

cataract surgery has an added value of creating precise arcuate corneal incisions.

Corneal topography should help to detect asymmetric corneal astigmatism and if

there is an irregular astigmatism then topography guided LASIK would be the best

option.

Editors’ note: Dr. Hutauruk has no fi nancial interests related to his comments.

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March 2013 13EWAP FEATURE

When performing LRIs, the main points are careful positioning, careful measure-ments, and careful placement

Source: Louis D. Nichamin, MD

and stability,” he said. “If you

have access to a femtosecond laser

for cataract surgery, there’s no

question that the incisions are

more accurate and more pristine

than a blade-created incision,” he

said.

Dr. Tipperman also described

Richard Mackool, MD’s penetrating

LRI nomogram, “where surgeons

take their keratome of choice (2.2-

2.5) and make one or two phaco

incisions directly on axis to reduce

the corneal astigmatism.” These

PLRIs are used just before the

viscoelastic is removed at the end

of the case, he said. The nomogram

shows that for 1.5 D of against-the-

rule (ATR) astigmatism, surgeons

should make two 3.2-mm incisions

180 degrees apart.

“If you average 100 patients,

you’ll have the 1.5 D of correction.

But some will have zero effect

and others will have a 2.5-D

effect,” Dr. Tipperman said. “And

that’s the issue with incisional

keratotomy—you may on average

get your desired effect, but there’s

going to be variability that’s hard

to control.”

Dr. Donnenfeld uses every

technique available but fi nds he

uses diamond knives “more at

the slit lamp to adjust the results

in patients who have surprises

postoperatively.”

Dr. Tipperman recommends

surgeons keep the blades

perpendicular to the limbus and

“go slow.” Study the patient’s

topography “and make sure it’s

symmetric and looks good before

treating,” he said. “It’s amazing

the number of people who want

to treat based on keratometry

readings alone.”

LRIsLast year’s ASCRS Innovator’s

Lecture clarifi ed what “posterior

corneal astigmatism” is (courtesy

of Douglas Koch, MD). Dr.

Nichamin said “one of the

ramifi cations of [this work] is that

we now have further evidence that

with-the-rule (WTR) astigmatism

behaves differently than ATR, and

that’s due in part to the posterior

corneal contributions.” Dr.

Nichamin’s LRI nomograms have

“for many years” been divided into

two separate tables—one for WTR

and the other for ATR.

“I’m probably a bit of an

anomaly because I separate them—

it’s not signifi cantly different,

and almost in the same ratio as

what [Dr. Koch] has pointed out

in terms of quantifi ed differences

that occur in the posterior corneal

measurements in the setting of

toric IOL use,” Dr. Nichamin

said. As such, Dr. Koch’s recent

fi ndings with regard to ATR versus

WTR astigmatism and its varying

response to correction through

the use of toric implants parallels

what he has experienced when

utilizing LRIs. “There’s still much

that we don’t understand and

until recently, did not measure

very well either.” For instance,

the limbus is a little closer to the

visual axis at 6 and 12 o’clock

as compared to 9 and 3 o’clock,

and “inter-” as well as “intra”-

corneal meridional differences can

complicate calculations; traditional

measurements tend to occur only

at two points in each meridian,

which may not be suffi cient.

Surgeons have also seen meridional

differences between Occidental

and Asian eyes.

“I’ve been a big proponent of

LRIs for a long time, but one of

the concerns with these incisions

is that every patient responds

differently based on multiple

parameters,” Dr. Donnenfeld

said, adding Dr. Koch’s work has

helped to clarify some of those

discrepancies. “It’s more of an art

form than science, and LRI results

can be variable even in the hands

of the best surgeons because of the

patient variability.”

LRIs remain a reasonable

option for anything under 1.0 D

or 1.5 D, Dr. Tipperman said, but

“based on Dr. Koch’s work, maybe

we should limit that to 0.75 D or

1.25 D if they’re WTR.”

Dr. Nichamin suggested that

all surgeons continually adjust

and refi ne their nomograms and

start thinking of them as fl uid

measurements rather than static

ones.

Femtosecond laserDr. Donnenfeld has begun

performing arcuate incisions with

a femtosecond laser “because

the accuracy is uncanny,” he

said. “The incisions are perfectly

symmetric so there is less irregular

astigmatism and none of the

surgeon variability that can be

present with manual LRIs.” With

the LenSx (Alcon), he uses a 9 mm

optical zone, and an 8 mm optical

zone with the IntraLase (AMO).

By titrating the incisions, “we’re

achieving superior outcomes.

Before the femtosecond laser, any

incision we made was permanent,”

he said. The femtosecond laser




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Modalities - from page 13

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allows surgeons to create the

incision but not fully open it

until deemed necessary, either

intraoperatively or post-op,

allowing the surgeon to adjust the

results.

“You don’t have to open the

incisions at the time of surgery,”

Dr. Tipperman said. “One of the

biggest advantages of the femto

incision is that it’s adjustable and

titratable.” He treats at 9 mm, and

“I use 90% of the nomogram and

about 85% depth.”

Dr. Nichamin has worked

with the LensAR (Orlando, Fla.,

USA) laser and although FDA

approval for relaxing incisions is

still pending, in the laboratory

“we have been able to create near

perfect incisions all the way out to

the limbus in most cases.”

ASCRS is working on

developing nomograms for the

different femtosecond lasers/

arcuate incisions.

Toric IOLsToric IOLs are still the

preferred treatment if patients

have undergone previous refractive

surgery, have higher levels of

astigmatism, or have thin corneas,

Dr. Nichamin said.

“Toric IOLs have been our

game changer in astigmatism

management” because of their

stability and predictability, Dr.

Tipperman said.

“I like toric lenses,” Dr.

Donnenfeld said. “They don’t have

the incisions, they don’t induce dry

eye, and they’re more accurate for

higher amounts of astigmatism.”

He routinely combines arcuate

incisions with toric IOLs and uses

the former as a template for where

to place the lens; he opens the

incisions post-op “if I need to do

any fi ne-tuning.”

Dr. Tipperman suggests

marking at 6 o’clock using a

circular marker and ensuring the

viscoelastic is removed at the end

of the procedure to avoid post-op

rotation.

“For surgeons to achieve

optimal results, they need to be

familiar with all of these treatment

modalities,” Dr. Nichamin said.

“You can’t hang your hat on

just one.” The decision of which

technique to use “is quite complex,

and there’s not one quick, simple

answer. It depends on the surgeon’s

comfort level, what technologies

are readily available, cost, and

perhaps most importantly, specifi c

patient characteristics.” EWAP

Editors’ note: Dr. Donnenfeld has fi nancial interests with Alcon and AMO. Dr. Nichamin has fi nancial

interests with LensAR. Dr. Tipperman has fi nancial interests with Alcon and Marco (Jacksonville, Fla., USA).

Contact informationDonnenfeld: 516-766-2519, [email protected]: 814-849-6547, [email protected]: 484-434-2716, [email protected]



Experts differ on corneal astigmatism correction in cataract surgeryby Erin L. Boyle EyeWorld Senior Staff Writer

Total corneal astigmatism

correction during cataract

surgery could be either by

eliminating it or leaving

slight with-the-rule astig-

matism

Corneal astigmatism

correction in cataract

surgery should achieve

zero residual astigmatism,

some experts say, but there is

also a theory that patients might

benefi t from one quarter to one

half a diopter (D) of with-the-rule

astigmatism because of against-the-

rule drift.

Jack T. Holladay, MD,

clinical professor of ophthalmology,

Baylor College of Medicine,

Houston, Texas, USA, said the

goal in corneal astigmatism

correction should be to eliminate it

completely.

“The idea that you should leave

a little with-the-rule and against-

the-rule are old myths that come

from articles written about 10 or

15 years ago,” said Dr. Holladay.

“It’s not true. Residual astigmatism

is like any other aberration. The

best vision and the best result are

with zero residual astigmatism and

with- or against-the-rule are not

benefi cial. They blur the image,

particularly if you don’t wear

glasses.”

The ultimate goal in patient

management for total corneal

astigmatism correction in cataract

surgery is both short-term and

long-term patient satisfaction, said

Douglas D. Koch, MD, professor

and the Allen, Mosbacher, and Law

Chair in ophthalmology, Cullen

Eye Institute, Baylor College of

Medicine. He said a key step in

achieving that goal is determining

patients’ needs.

“If we go to the assumption

that most patients want to see

clearly at some distance without

glasses, and therefore have a

signifi cant reduction of their

astigmatism, the goal in my mind

would be a small amount of with-

the-rule astigmatism, around 0.25

D or at most 0.5 D, the reason

for that being there’s a long-term

against-the-rule shift that takes

place. If you leave patients with

just a little bit of with-the-rule

astigmatism, that will enable them

to maintain a relatively small

amount of astigmatism over a long

period of time,” Dr. Koch said.

“We should also recognize that

occasionally patients do well with

myopic astigmatism, which gives

them greater depth of focus, but at

the expense of clear vision at any

distance. It is diffi cult to predict

those who might like this, so I

rarely recommend it,” he said.

Patient ageDr. Koch has been researching

corneal astigmatism and toric IOL

selection in cataract surgery cases.

He has developed a nomogram that

incorporates the mean posterior

corneal astigmatism in eyes with

either with-the-rule astigmatism

or against-the-rule astigmatism

and the effect of against-the-rule

drift that happens with aging.

Warren E. Hill, MD, East Valley

Ophthalmology, Mesa, Ariz., USA,

said that he follows Dr. Koch’s

recommendation of leaving patients

with one quarter to one half a D of

with-the-rule astigmatism as the

fi nal operative goal.

“I think that’s a very good

strategy. Typically what happens

for the older patients is that they

may gain a little against-the-rule

astigmatism over time, so if you

leave them with some with-the-

rule astigmatism, they’ll always be

changing toward something better

[rather] than away from what it

is that they want,” said Dr. Hill.

AT A GLANCE• Some experts say the goal

in total corneal astigmatism

correction is eliminating it.

• Theory postulates that one

quarter to one half D of with-

the-rule astigmatism could

be effective.

• Against-the-rule drift that

happens with age could play

a role in effectiveness.

• With-the-rule astigmatism

cases are easier to treat,

expert says. Dual Scheimpfl ug image showing more than 3 D of WTR astigmatism on the anterior cornea and –0.65 on the posterior cornea (which has an ATR refractive effect)

Source: Douglas Koch, MD, and Wang Li, MD

n nd




“Younger patients are completely

different. They’re going to drift

toward against-the-rule over time,

but it may take decades. We’re very

good at taking care of the older

patients, but the younger patients

still have some questions that need

to be answered.”

Dr. Koch said that it could be

argued that with an 85-year-old

patient, with-the-rule astigmatism

is not needed, as there is not likely

to be signifi cant change over the

course of the patient’s life. “On the

other hand, an 85-year-old could

live to 95, and you could argue

that a 50-year-old will have a much

greater chance of against-the-rule

shift, so you might leave them more

with-the-rule,” he said.

“My philosophy is, most of

these folks, if they want their

astigmatism corrected, they want it

corrected so they have good vision

now,” Dr. Koch said. “So the goal

in my mind is to leave them with

just a little bit, just enough that

they will have great uncorrected

vision, and then you can deal with

the against-the-rule shift as it takes

place in a 50-year-old—if it takes

place in 15 years, then you can

treat it at that time. But I think the

50-year-old would be disappointed

if you left him or her at 1 D of with-

the-rule astigmatism with blurry

vision planning that far ahead,

unless that patient’s a special kind

of patient and really understands

that concept.”

With-the-rule astigmatismDr. Koch said that he fi nds

with-the-rule astigmatism cases (as

measured on the anterior corneal

surface) require lower amounts

of correction per unit diopter of

astigmatism because of the against-

the-rule refractive effect on the

back of the eye. He bases this on

data from a recently published

study in which posterior corneal

astigmatism was measured with a

dual Scheimpfl ug device1 and from

analysis of clinical results with toric

IOLs.

“These patients often don’t

need much, and they need a lot less

than we used to think. That applies

to relaxing incisions and it applies

to toric lenses,” he said.

Dr. Holladay said that Dr. Koch

and others have found that those

with-the-rule astigmatism cases

need a different amount of cylinder

than against-the-rule cases.

“[Dr. Koch’s] observation has

been that whether it’s with-the-rule

or against-the-rule astigmatism,

for some reason, they end up with

more or less residual,” Dr. Holladay

said.

“The question is, why?” he said.

“What I’ve told [Dr. Koch] is, we’ve

got to pin down what the reason

for that is, if it’s to make sense. …

it’s possible that it may be due to

the fact that the with- and against-

the-rule astigmatism have different

posterior corneal astigmatisms,

and if that’s true, we should be

able to see that with Scheimpfl ug

devices like the Pentacam [Oculus,

Lynnwood, Wash., USA] and the

Galilei [Dual Scheimpfl ug Analyzer,

Ziemer, Port, Switzerland] and be

able to show that it’s a result of

the posterior surface. That’s one

possibility—that the posterior

cornea might have an effect, and

that’s what he believes. But we’ve

looked at the Pentacam and Galilei

and that’s not supported yet.”

Other reasons could exist,

Dr. Holladay said, including the

fact that, regardless of whether

a horizontal or vertical cataract

incision is made in what location,

patients drift in the direction of

against-the-rule with age.

“The other possibility is that

when you put an implant in,

that implant is never parallel

or perpendicular to the visual

axis; it may be tilted a little bit

and that tilt induces a small

amount of astigmatism. That’s

under investigation right now.

In other words, that’s [Dr.

Koch’s] observation, but there’s

no mechanism yet that’s been

confi rming that that observation

may be correct. The reason for that

observation is still up in the air,”

Dr. Holladay said.

Against-the-rule astigmatismAccording to Dr. Koch, against-

the-rule astigmatism cases need

more adjustment than with-the-rule

cases because the posterior cornea

“increases the amount of against-

the-rule astigmatism.”

“So in using a toric IOL, you

want to go up at least one half D of

increased correction for the against-

the-rule patient, and in terms of

relaxing incisions for the against-

the-rule patient, yes, they are more

likely to need it, even if there’s a

small amount of against-the-rule,”

he said.

The diffi cult part of against-

the-rule astigmatism cases is that

relaxing incisions must not be

made too long, he said. If they are,

they can create dryness and foreign

body sensation because of incised

corneal nerves.

“That astigmatism, in my mind,

is more challenging to treat,” Dr.

Koch said. “I more often will go to a

toric lens and do a relaxing incision

in those, whereas more often in

with-the-rules, for amounts up to 1

D, I do nothing and will not use a

1 D toric IOL until anterior corneal

with-the-rule astigmatism is 1.7 D.”

Dr. Holladay said in some

cases, despite the best planning,

the outcome is still not as desired.

In those cases, his Holladay IOL

Consultant has a Toric Back

Calculator tab that provides

physicians with a second chance.

“It allows the surgeon to take

the observed axis of the lens and

the refraction and by observed

axis, you look in with the slit lamp,

you line up the slit beam and you

say, that lens is at 45 degrees. And

then, if you refract the patient, with

those two bits of information, I can

calculate for you exactly how much

you need to rotate that lens to the

perfect position,” he said.

He also recommended that

physicians look at the post-op

refraction and observed axis or

post-op refraction and K reading.

“When you do end up with

an outcome that’s not on the

button, you use that Toric Back

Calculator to fi nd out how much

you need to rotate it to get it to

the right position. That helps a lot,

and it tells you what the residual

astigmatism is,” he said. EWAP

Reference1. Koch D, Ali SF, Weikert MP,

Shirayama M, Jenkins R, and

Wang L. Contribution of posterior

corneal astigmatism to total

corneal astigmatism. J Refract Surg.

2012;38:2080-2087.

Editors’ note: Dr. Hill has fi nancial

interests with Alcon (Fort Worth,

Texas, USA/Hünenberg, Switzerland).

Dr. Holladay is the developer of the

Holladay IOL Consultant programs.

Dr. Koch has fi nancial interests

with Alcon, Abbott Medical Optics

(Santa Ana, Calif., USA), OptiMedica

(Sunnyvale, Calif., USA), and Ziemer.

Contact information

Hill: 480-981-6111, [email protected]

Holladay: [email protected]

Koch: 713-798-6443,

[email protected]

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Experts - from page 15



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Posterior corneal astigmatism vital to calculating correct total astigmatismby Erin L. Boyle EyeWorld Senior Staff Writer

Not measuring the posterior

corneal astigmatism

could result in incorrect

estimation of total corneal

astigmatism, hindering toric IOL

selection through overcorrection

in with-the-rule astigmatism and

undercorrection in against-the-rule

astigmatism, researchers found.

Douglas D. Koch, MD,

professor and the Allen, Mosbacher,

and Law Chair in ophthalmology,

Cullen Eye Institute, Baylor College

of Medicine, Houston, Texas, USA,

and Li Wang, MD, associate

professor, Cullen Eye Institute,

Baylor College of Medicine,

Houston, are researching the effect

of posterior corneal astigmatism

and toric IOL selection in cataract

surgery cases.

Dr. Wang said both posterior

and anterior corneal astigmatism

measurements are important to all

cases undergoing cataract surgery.

“It would be best to measure

posterior corneal astigmatism,” she

said. “The magnitude of posterior

corneal astigmatism cannot be

predicted based on the amount of

anterior corneal astigmatism. If

there is no access to a device that

measures the posterior corneal

astigmatism, the average value of

the posterior corneal astigmatism

may be used.”

Drs. Koch and Wang and

colleagues published study results

on the topic in the Journal of

Cataract & Refractive Surgery. They

evaluated 715 corneas of 435

consecutive patients, calculating

total corneal astigmatism using ray

tracing, corneal astigmatism from

simulated keratometry, anterior

corneal astigmatism, and posterior

corneal astigmatism.

They found that toric IOL

selection based on anterior corneal

measurements only could lead to

problems.

“Patients who have anterior

Posterior corneal astigmatism

Baylor toric IOL nomogramSource (all): Douglas D. Koch, MD, and Li Wang, MD

with-the-rule astigmatism—in

other words, the cornea is steep

at 90 degrees anteriorly—tend to

have, on average, 0.5 diopter (D)

of steepness vertically along the

posterior cornea, and because the

posterior cornea is a minus lens,

steepness vertically translates into

power horizontally or against-

the-rule effect refractive power at

180,” Dr. Koch said. “So you might

measure a patient who has 2 D on

the anterior cornea. And when all

is said and done, that patient may

only have 1.3 or 1.4 D on the total

corneal power because the posterior

cornea throws in about 0.5 or 0.6 D

in the other direction.”

Measuring devicesMeasuring posterior corneal

astigmatism is a challenge, Dr. Koch

said. Two devices on the market,

the Galilei Dual Scheimpfl ug

Analyzer (Ziemer, Port, Switzerland)

and the Pentacam (Oculus,

Lynnwood, Wash., USA), measure it

“moderately accurately,” he said.




Views from Asia-Pacifi cSri GANESH, MDChairman and Managing Director, Nethradhama Hospitals Pvt. Ltd.26/14, Kanakapura Main Road, 7th Block Jayanagar Bangalore 560082 IndiaTel. no. +91-80-26088000/+91-98451294740Fax no. [email protected]

As cataract and refractive surgeons, we are constantly in pursuit of ensuring that our patients attain maximum uncorrected visual acuity after our interventions. Residual refractive astigmatism contributes signifi cantly

to the refractive outcomes of the surgery. Not measuring posterior corneal astigmatism may be one of the reasons for unexpected postoperative astigmatism, especially after toric IOLs.

Despite correct IOL calculation with the standard parameters, IOL placement and alignment, surgeons encounter a refractive surprise. There may be overcorrection of with-the-rule astigmatism and undercorrection of against-the-rule astigmatism. This can be attributed to the posterior corneal astigmatism. Anterior corneal astigmatism in younger individuals is with-the-rule and in older individuals it is against-the-rule. In contrast, the posterior cornea has a steeper vertical axis which effectively causes against-the-rule astigmatism, since the posterior cornea tends to act as a minus lens. Therefore, the anterior with-the-rule astigmatism is reduced and the anterior against-the-rule astigmatism is enhanced due to the posterior corneal astigmatism in most cases.

As pointed out by the authors, estimation of posterior corneal astigmatism should be done routinely in toric IOL patients in addition to the standard parameters. If there is no access to the available devices to estimate the posterior astigmatism, then the data available in Dr. Koch’s nomogram or the Baylor’s nomogram can be used to estimate the mean posterior corneal astigmatism to calculate the toric IOL power and axis. One more important fact pointed out by the authors is that it is essential to keep in mind the effect of against-the-rule drift that occurs with age. Hence, it is always better to leave the toric IOL patient with some amount of residual with-the-rule astigmatism to compensate for the against-the-rule drift which occurs with aging. Imaging the posterior corneal astigmatism can be done on all patients posted for refractive cataract procedures in particular toric IOLs and toric multifocal IOLs thereby enhance the outcome.

The posterior corneal surface acts like a negative lens due to the relative change in the corneal thickness from periphery to center. This may be the reason that some eyes having with-the-rule astigmatism may have a higher overcorrection than others following toric IOL implantation. It would probably be a good idea to assess the effect of posterior corneal astigmatism in relation to the relative change in corneal thickness or progression of corneal thickness from periphery to center. Depending upon the central corneal thickness an average correction factor could be derived to compensate for the posterior corneal astigmatism and this could be incorporated into the formula for calculating the power of the toric IOL. This could help practices

that do not have Scheimpfl ug devices to measure the posterior corneal astigmatism.

Editors’ note: Dr. Ganesh is a consultant for Abbott Medical Optics (Santa Ana, Calif., USA), Carl Zeiss (Jena, Germany), Hoya Surgical Optics (Chino Hills, Calif., USA), Bausch + Lomb (Rochester, NY, USA), and Schwind eye-tech-solutions (Kleinostheim, Germany), but has no fi nancial interests related to his comments.

“I think that our measurements

could improve,” Dr. Koch said. “We

do fi nd that even the Galilei, which

has a wonderful dual Scheimpfl ug

with against-the-rule astigmatism,”

he said.

He cited a long-term study

by K. Hayashi and colleagues

that followed patients’ astigmatic

change after undergoing 3-mm

clear corneal temporal incisions.

The study also had a control group

that did not undergo cataract

surgery.

Researchers found that both

groups had a comparable change

of against-the-rule shift after more

than 10 years.

“You would think that a

corneal incision temporarily might

weaken the cornea such that the

cornea would not steepen along

the horizontal meridian over time.

But in fact it does,” Dr. Koch said.

“So in planning for our patients, I

believe that we need to leave our

patients a little bit on the with-the-

rule side in order to compensate

for the fact that they’re going to

drift to against-the-rule over time.

This will provide them with better

uncorrected acuity over a much

longer period of time and perhaps

serve them well for 20 or more

years.” EWAP

References1. Hayashi K, Hirata A, Manabe S,

Hayashi H. Long-term change in

corneal astigmatism after sutureless

cataract surgery. Am J Ophthalmol.

2011 May;151(5):858-65.

2. Koch DD, Ali SF, Weikert MP,

Shirayama M, Jenkins R, Wang L.

Contribution of posterior corneal

astigmatism to total corneal

astigmatism. J Cataract Refract Surg.

2012 Oct 12. [Epub ahead of print]

Editors’ note: Dr. Wang has fi nancial

interests with Ziemer. Dr. Koch has

fi nancial interests with Ziemer, Alcon

(Fort Worth, Texas, USA/Hünenberg,

Switzerland), Abbott Medical Optics

(Santa Ana, Calif., USA), and

OptiMedica (Sunnyvale, Calif., USA).

Contact information

Wang: 713-798-7946, [email protected]

Koch: 713-798-6443, [email protected]

mechanism for measuring the

back, does not always seem to

capture all of the posterior corneal

astigmatism, and especially in

patients [who have] with-the-

rule astigmatism, it still seems

to underestimate the amount of

posterior corneal astigmatism based

on our actual refractive outcomes.”

Dr. Koch has created a

nomogram that incorporates: 1) the

mean posterior corneal astigmatism

in eyes having either with-the-rule

or against-the-rule astigmatism

and 2) the effect of against-the-rule

drift that occurs with age. He said

that their data indicate that the

new nomogram greatly improves

accuracy with toric IOLs.

In addition, manufacturers are

interested in providing clinicians

with this information because

they are fi nding similar results

retrospectively in their data, he

said.

However, to disseminate a new

nomogram themselves, they would

have to validate it in a clinical trial

with the U.S. FDA, which could

slow the approval process.

Toric IOLsDr. Koch began examining

posterior corneal astigmatism

when he noticed that some patients

had unexpected results with toric

IOLs. Patients who had with-

the-rule astigmatism were being

overcorrected, while patients who

had against-the-rule astigmatism

were undercorrected.

“It has a huge impact on my

decision making now in patients

who are seeking astigmatic

correction during cataract surgery,”

Dr. Koch said. “It’s completely

changed everything I’m doing with

regard to both relaxing incisions

and with regard to the selection of

toric IOLs.

“I have backed off on toric IOL

power in patients who have with-

the-rule astigmatism and conversely

ramped it up for those patients with

against-the-rule. For example, for

someone who has 1 diopter with-

the-rule astigmatism, I will not put

a toric IOL in because I am likely

to overcorrect him and leave him

Posterior - from page 17


19EWAP CATARACT/IOLMarch 2013

A new complication after endothelial keratoplasty proceduresby Vanessa Caceres EyeWorld Contributing Writer

Opacifi cation, calcifi cation

linked to a certain type of

IOL material

Surgeons may want to

avoid hydrophilic acrylic

lenses when performing

cataract surgery either

concurrently or in a patient at risk

for an endothelial keratoplasty

procedure, a number of fellow

surgeons are reporting.

That’s because these surgeons

are fi nding they have to explant

the IOLs after IOL calcifi cation

forms right where the visual axis

and air bubble were in contact,

causing opacifi cation and

essentially decreasing a patient’s

vision, said W. Barry Lee, MD,

Cornea, External Disease, &

Refractive Surgery, Eye Consultants

of Atlanta/Piedmont Hospital,

Atlanta, Ga., USA.

“It’s clear that the air bubble is

reacting to the hydrophilic acrylic

lens material and causing a buildup

of hydroxyapatite. Over time it

gets more opacifi ed and eventually

leads to a drop in vision,” Dr. Lee

said. “The problem is its directly

in the patient’s central vision so

we very likely have to do a lens

explant, which is risky for the

endothelial transplant survival.”

Tracking the problemThis is a new problem related

to endothelial keratoplasty

procedures as this kind of surgery

has only been around a few years,

Dr. Lee said. However, calcifi cation

of some hydrophilic IOLs

previously occurred one to two

years after cataract surgery, said

Nick Mamalis, MD, professor

of ophthalmology, John A.

Moran Eye Center, Department of

Ophthalmology & Visual Sciences,

University of Utah, Salt Lake City,

Utah, USA. The calcifi cation in

those cases occurred in different

locations and for different reasons.

Surgeons rarely if ever have seen

that kind of calcifi cation with

modern hydrophilic IOLs until

the localized calcifi cation after

Descemet’s stripping endothelial

keratoplasty (DSEK) or Descemet’s

stripping automated endothelial

keratoplasty (DSAEK) began to

occur, he said.

Although Dr. Lee said there

are few published reports on this

problem right now, he said there

is even more word-of-mouth

evidence from surgeons that this

problem is occurring more often.

Additionally, a report of three cases

in the October 2012 issue of Cornea

by Patryn et al. as well as a letter in

the April 2012 issue of the Journal

of Cataract & Refractive Surgery

(JCRS) from Werner et al. have

addressed the problem.

“We have recently published

a letter calling attention to a

phenomenon of calcifi cation

of intraocular lenses following

procedures using intracameral

injections of air or gas, including

posterior lamellar keratoplasty

techniques,” said Liliana

Werner, MD, associate professor

and co-director, Intermountain

Opacifi ed Memory Lens after DSAEK

Opacifi ed Rayner IOL after DSAEK. After dilation, the hydroxyapatite respects the visual axis and only coats the anterior surface of the IOL where the previously undilated pupil was present. The iris protected the remainder of the IOL from opacifi ca-tion.

Source (all): W. Barry Lee, MD

Ocular Research Center,

Department of Ophthalmology

and Visual Sciences, John A. Moran

Eye Center, referring to the JCRS

letter. “Since that publication,

we have received new specimens

in our laboratory at the John A.

Moran Eye Center represented

by lenses calcifi ed after DSEK or

DSAEK.”

The exact cause and how

often the problem is occurring are

not yet clear, Dr. Mamalis said.

“Something is changing on the

anterior surface of the IOL. We’re

trying to fi gure out what it is,” he

said.

The problem does not seem

to be linked with IOLs from a

particular manufacturer, Dr.

Werner said. All lenses studied by

Dr. Werner and co-investigators

have a distinctive pattern of

calcifi cation localized to the

anterior surface/subsurface of the

lens and within the pupillary or

the capsulorhexis area.

“The calcifi cation was very

dense and could not be removed

by Nd:YAG laser applications or

surgical means, and the lenses had

to be explanted due to decrease in

visual function,” Dr. Werner said.

Dr. Werner’s letter discusses

the circumstances surrounding

the handful of reported cases

where this problem has occurred.

One such case analyzed at her lab

had localized IOL calcifi cation

after DSAEK. In June 2010, the

patient had Fuchs’ dystrophy and

phacoemulsifi cation, followed by continued on page 21

19-32 EW CARARACT.indd 1919-32 EW CARARACT.indd 19 22/03/2013 11:5222/03/2013 11:52

20 EWAP CATARACT/IOL March 2013

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hydrophilic IOL implantation. The

DSAEK procedure was performed

with intracameral injections of

air in October 2010. “Two months

later, the patient complained

of ‘foggy’ vision,” Dr. Werner

and co-investigators reported.

“Opacifi cation of the anterior

surface of the IOL within the

pupillary area was observed. As

Nd:YAG laser disruption of the

opacifi cation was not successful,

surgeons exchanged the IOL in

October 2011.”

ImplicationsThe easiest way to prevent this

problem is to avoid hydrophilic

acrylic lenses in patients where

cataract surgery is needed

concurrently or prior to DSEK or

DSAEK. Surgeons should instead

use hydrophobic lenses in those

patients.

“For the moment, surgeons

should consider avoiding

hydrophilic acrylic IOLs when

procedures using intracameral air

or gas are anticipated, particularly

in DSEK or DSAEK,” Dr. Werner

said.

Generally speaking, surgeons

in Europe use hydrophilic lenses

more often, said Dr. Mamalis.

However, even surgeons in the

U.S. may have their personal

preferences for the material,

Dr. Lee said. In Dr. Lee’s offi ce,

some surgeons favor the use of

hydrophilic acrylic lenses in

routine cataract cases, and they

work great in most cases—except

for in two patients in whom the

hydrophilic acrylic IOLs had to

be explanted after endothelial

keratoplasty procedures due to

severe opacifi cation and vision

decline. In both cases the DSAEK

was performed for advanced Fuchs’

dystrophy following prior cataract

surgery. The IOL explantation

occurred with the fi rst year

after the DSAEK procedures. IOL

explantation under an endothelial

graft carries a high risk for

potential endothelial graft damage.

“If a patient is going to have

combined DSAEK and cataract

removal, or if it is a patient with

Fuchs’ dystrophy and you see

moderate to advanced guttata,

avoid hydrophilic acrylic lenses in

those cases,” Dr. Lee said. “This

is another thing to think about

when you see patients with Fuchs’

dystrophy to avoid a potential

serious complication.”

However, this area requires

further research, Dr. Werner

believes.

“Further investigation in

this phenomenon is necessary

to ascertain if the localized

calcifi cation is a result of direct

contact between the IOL surface

and the exogenous gas and air, of

a metabolic change in the anterior

chamber due to the presence of the

exogenous gas and air, or the result

of an exacerbated infl ammatory

reaction after multiple surgical

procedures,” said Dr. Werner. EWAP

Editors’ note: The physicians have

no fi nancial interests related to this

article.

Contact information

Lee: 404-351-2220, [email protected]

Mamalis: 801-581-6586,

[email protected]

Werner: 801-581-8136,

[email protected]

A new - from page 19

TECNIS® Monofocal Intraocular Lens (IOL)Warnings: Physicians considering lens implantation under any of the conditions described in the Directions for Use labeling should

Precautionsirrigating solutions such as balanced salt solution or sterile normal

Adverse Events: The most frequently reported adverse event that occurred during the clinical trial of the 1-Piece lens was

surgical intervention (pars plana vitrectomy with membrane peel)

TECNIS® Multifocal 1-Piece Intraocular Lens (IOL)Warnings: Physicians considering lens implantation under any of the conditions described in the Directions for Use labeling

expected because of the superposition of focused and unfocused

percentage of patients, the observation of such phenomena will be annoying and may be perceived as a hindrance, particularly

contrast sensitivity is reduced with a multifocal lens compared

should exercise caution when driving at night or in poor-visibility

be taken to achieve centration, as lens decentration may result in patients experiencing visual disturbances, particularly in patients

Precautions: The central one millimeter area of the lens creates a far image focus; therefore, patients with abnormally small pupils (~1mm) should achieve, at a minimum, the prescribed distance vision under photopic conditions; however, because this multifocal design has not been tested in patients with abnormally small pupils, it is

Autorefractors may not provide optimal postoperative refraction of

contact lens wearers, surgeons should establish corneal stability

should be taken when performing wavefront measurements, as two different wavefronts are produced (one will be in focus [either far or near], and the other will be out of focus); therefore, incorrect

therefore, implant patients should be monitored postoperatively

occasionally in patients with controlled glaucoma who received

targeted, as this lens is designed for optimum visual performance Adverse Events: The most

frequently reported adverse event that occurred during the clinical ®

retinal repair, iris prolapse/wound repair, trabeculectomy, lens

The second most frequent adverse event was macular edema,

Caution: Federal law restricts these devices to sale by or on the

Attention: Reference the Directions for Use labeling for a

Important Safety Information



Preventing the Argentinian Flag Sign: Phaco capsulotomyby Christopher C. Teng, MD

The Argentinian

Flag Sign occurs

during capsulorhexis

construction. Due to

the overbearing pressure of the

cataract, the anterior capsule tears

and extends to the periphery.

Once this occurs, the remainder

of the cataract extraction can

become extremely difficult and

can lead to many complications,

such as posterior capsule rupture,

vitreous loss, retained nucleus,

and endothelial damage due to

prolonged surgery time.

Phaco capsulotomy is

a technique in which the

phacoemulsification tip is

used to simultaneously create

the initial tear in the anterior

capsule and remove a portion of

the intumescent lens, thereby

debulking and relieving pressure

from the lens and capsule, and

preventing the Argentinian Flag

Sign.

IntroductionWhite cataracts and

intumescent cataracts are

challenging cases for most

surgeons. In these eyes,

during capsulorhexis creation,

the pressure created by the

hyperhydration of lens fibers can

cause spontaneous tears in the

capsulorhexis that extend to the

periphery.

When this occurs, the

appearance of the stained

blue anterior capsule beside

the white cataract mimics the

blue-white-blue pattern of the

Argentinian flag and was named

the Argentinian Flag Sign (Figure

1). Daniel Mario Perrone, MD,

coined the term, and his video

won awards at the 2000 American

Society of Cataract & Refractive

Surgery and the European Society

of Cataract & Refractive Surgeons

annual meetings.

One method for preventing

the Argentinian Flag Sign is by

introducing a 27-gauge needle

on a syringe into an intact

anterior capsule. The needle is

used to aspirate the liquefied

cortex, thereby depressurizing

the nucleus, which facilitates

a controlled capsulorhexis.1

Additionally, a highly cohesive

ophthalmic viscosurgical device

(OVD) can be used to pressurize

the anterior chamber against the

pressure of the intumescent lens,

which can facilitate continuous

curvilinear capsulorhexis (CCC)

completion.2 Alternatively, a

CCC can be created using a two-

stage technique, which can help

prevent unexpected radial tears.3

The phaco capsulotomy

technique, which likely first

originated in India, introduces the

phacoemulsification tip through

the center of an intact anterior

capsule and aspirates a portion

of the lens. This simultaneously

creates the initial anterior capsule

puncture and removes some of

the liquefied cortex and nucleus.

Phaco capsulotomy debulks and

depressurizes the entire lens/

capsule apparatus, and removes

the impetus for the capsule to

tear outward. Once enough of

the cortex is aspirated, OVD

is injected and a leaflet of the

capsule can be grasped with a

forceps, and the capsulorhexis

can be completed without

complication.

TechniqueThe initial steps are identical

to a cataract extraction in which

capsular stain is used. This includes

creating a paracentesis, using a

capsular stain, injecting highly

cohesive and/or dispersive OVD,

and creating a main wound.

After the main wound is created,

the phacoemulsifi cation tip is

introduced into the eye. The

handpiece should not be irrigating

upon entry, as there is OVD

present in the anterior chamber

that maintains anterior chamber

form. The bevel of the tip should

be positioned facing up, as this

best facilitates removal of liquefi ed

cortex and underlying nucleus.

Next, the phacoemulsifi cation tip

should be directed at a downward

angle and situated over the center

of the anterior capsule.

The settings on a torsional

phacoemulsifi cation machine

should be in the sculpting mode,

with no phacoemulsifi cation

power but high phaco handpiece

Figure 1. Argentinian Flag Sign. Arrow indicates tear of the anterior capsule, which extends to the periphery.

Figure 2B. Ophthalmic viscosurgical device injected into the anterior chamber, with good visualization of the capsular tear

Figure 2C. Completion of a continuous curvilinear capsulorhexis

Source (all): Christopher C. Teng, MD

Figure 2A. Phaco tip puncturing an intact anterior capsule and aspirating and debulk-ing the nucleus




s

D

CHEE Soon Phaik, MDSenior Consultant and Head, Cataract Subspecialty Service and Ocular Infl ammation & Immunology,Singapore National Eye CentreAssociate Professor, Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, and Duke-National University of Singapore Post Graduate Medical School, Singapore, Singapore Eye Research Institute

11 Third Hospital Avenue, Singapore 168751Tel. no. +65-62277255Fax no. [email protected]

Creating an intact continuous curvilinear capsulorhexis (CCC) for the intumescent cataract always poses a challenge for the cataract surgeon. This step is crucial for phacoemulsifi cation especially when dealing with a dense

nucleus. In eyes with shallow anterior chamber, the intumescent lens may present as phacomorphic glaucoma, complicating the surgery further.

There are various ways of avoiding the Argentinian Flag Sign. This article describes the “phaco capsulotomy”, which I have had no personal experience with. I am reluctant to use this technique for fear of creating a leading edge (as seen in Figure 2B) which may extend in an uncontrolled fashion during the initial maneuver. If the phaco tip becomes occluded, resulting in impaling of the nucleus, further aspiration of the liquefi ed cortex will cease, allowing the tear to propagate.

I routinely use the needle aspiration method, which has rarely failed in my hands. Here are some tips for a successful outcome:

1. Run intravenous mannitol to shrink the vitreous and swollen lens a half hour prior to surgery even in the absence of raised intraocular pressure.

2. Avoid speculums that exert pressure on the globe.

3. Have a low threshold for giving regional anesthetic block in an uncooperative squeezing patient.

4. Always use capsular dye to ensure visibility of the anterior capsule. Apply the dye directly onto the capsule under viscoelastic to avoid staining of the endothelium of a swollen cornea.

5. Fill the eye with Healon 5 (Abbott Medical Optics, Santa Ana, Calif., USA) in the presence of signifi cant positive pressure until the anterior capsule is fl attened.

6. Enter the eye only partially with the keratome in order to keep the main incision small, thus minimizing viscoelastic loss and maintaining a deep anterior chamber. Enlarge the incision once lens decompression is successful.

7. Perform trans pars plana 23-gauge limited anterior vitrectomy to decompress the eye if the anterior chamber is still extremely shallow and the anterior capsule is bulging.

8. While holding a 1-cc syringe fi tted with a 27-gauge needle bevel up, simultaneously puncture the anterior capsule and aspirate liquefi ed cortex, pressing down on the nucleus. Rotate the bevel sideways without extending the breach in the anterior. Ballot the nucleus and continue aspiration as liquefi ed cortex from behind the nucleus is displaced anteriorly.

9. Fill the anterior chamber with retentive viscoelastic and complete the CCC. Use intraocular capsulorhexis forceps if the lens is still swollen.

Editors’ note: Prof. Chee is a consultant for Bausch + Lomb/Technolas Perfect Vision (Rochester, NY, USA/Munich, Germany), and Hoya Surgical Optics Pte. Ltd. (Chino Hills, Calif., USA), but has no fi nancial interests in the content of her comments.2007;33:47-52.

Views from Asia-Pacifi cYAO Ke, MDProfessor, Eye Center, Second Affi liated Hospital, College of Medicine, Zhejiang University88 Jiefang Road, Hangzhou 310009, Zhejiang Province, ChinaTel. no. +86-571-87783897Fax no. [email protected]

When a highly intumescent, bulging white lens is seen under the surgical

microscope, the surgeon will usually pause and hope that a rapid tear

of the anterior capsule to the lens equator would not happen. White and

intumescent cataracts are common in China, especially in the remote countryside.

The incidence of white cataracts is 5 to 10% in our Eye Center, Second Affi liated

Hospital of Zhejiang University. Fortunately, the Argentinian Flag Sign occurs in only

10% or less of these cases. It is a kind of challenge for the cataract surgeon to

perform the remaining surgery.

When I meet a white and intumescent cataract, it is necessary to evaluate the

possibility of the Argentinian Flag Sign before capsulorhexis. For the white cataract

without a liquefi ed cortex, capsulorhexis would be performed directly after the

capsular staining and OVD injection. If the injection of OVD can change the shape

of the lens surface due to the liquefi ed cortex, there is a risk of the Argentinian

Flag Sign developing. In these cases, I would inject a highly cohesive OVD from the

anterior chamber central and fl at the central anterior capsule as much as possible.

Adequate anterior chamber formation facilitates the following steps although it

requires more OVD. Then, a 27-guage needle on a syringe is introduced into the

center of the anterior capsule with a downward angle and the liquefi ed cortex is

aspirated simultaneously to depressurize the underlying nucleus, which is defi nitely

an effective method to prevent the Argentinian Flag Sign. As long as the anterior

capsule does not tear and extend to the periphery when punctured, the risk will

be reduced greatly with the aspiration of the liquefi ed cortex. Additionally, once

enough liquefi ed cortex is aspirated, OVD can be used to pressurize the anterior

capsule, followed by capsulorhexis. A leafl et of the capsule should be grasped and

torn concentrically with forceps during capsulorhexis. Any outward force can easily

tear the capsule to the lens equator because of the brittle anterior capsule.

I have not performed the phaco capsulotomy presented by Dr. Teng for dealing

with white and intumescent cataracts. According to the introduction, I think it is a

nice method worth being popularized. The point of my comments is that regardless

of which method you use, if the Argentinian Flag Sign does occur, be cautious

in deciding whether to continue phacoemulsifi cation. Meeting a hard and large

nucleus, switching to ECCE and circling out the nucleus by widening the incision

can avoid many serious complications such as rupture of the posterior capsule and

nucleus dislocation into the vitreous.

Editors’ note: Prof. Yao has no fi nancial interests related to his comments.

24



torsion, low vacuum, and moderate

aspiration. When the foot pedal

of the phacoemulsifi cation unit is

depressed, irrigation and aspiration

is introduced at a fi xed rate. Various

settings can be used depending on

the phacoemulsifi cation machine

used.

The next sequence of events

occurs simultaneously. The foot

pedal is depressed and the anterior

capsule is punctured with the

phaco tip. This creates the initial

anterior capsule puncture, and

the phaco tip is introduced into

the lens (Figure 2A). Milky cortex

will become visible and is quickly

aspirated into the handpiece. The

phaco tip is further embedded into

the nucleus to sculpt the nucleus

and further remove the milky

cortex. This sculpting motion can

be made repeatedly, with each

successive motion removing more

of the lens.

Once the surgeon determines

that enough of the cortex and fl uid

is removed, the phaco handpiece

is removed from the eye. OVD is

then injected to refi ll the anterior

chamber and the nonuniform

tear of the anterior capsule can be

visualized (Figure 2B). Next, using

a capsulorhexis forceps, a leafl et of

the anterior capsule can be grasped,

and the capsulorhexis can be

completed in a curvilinear fashion

(Figure 2C).

Hydrodissection can then be

performed and nucleus removal can

be performed in the usual fashion.

DiscussionPhaco capsulotomy is an

effective technique to debulk the

lens and remove the impetus for

the Argentinian Flag Sign to occur.

The main complication that I have

encountered using this technique is

wound burn. This occurs when the

phaco tip embeds immediately into

the nucleus and occludes, leading

to an interruption of aspiration.

Wound burn can be effectively

countered by pulsing the foot pedal

upon entry of the phaco tip or by

using burst mode.

Pearls to performing this

technique include using a second

instrument and using a 2.75-mm

wound and larger phaco tip. Eyes

with mature intumescent lenses

frequently have shallow anterior

chambers, and when the phaco

tip is introduced, the eye will

be pushed to a nasal position. A

second instrument can be placed

into the paracentesis to pull the eye

back to an ortho position before the

phaco capsulotomy is performed. A

larger wound and phaco tip are also

advantageous because there is less

chance of the handpiece becoming

occluded, thereby decreasing the

risk of wound burn and facilitating

removal of the dense lens

fragments.

In conclusion, phaco

capsulotomy is a safe and effective

technique for preventing the

Argentinian Flag Sign. By using

the phaco tip to simultaneously

create an anterior capsular puncture

and remove the liquefi ed cortex

and nucleus, the lens/capsule

apparatus is decompressed and

the impetus for the capsulorhexis

to spontaneously tear outward is

eliminated. EWAP

References1. Rao SK, Padmanabhan P.

Capsulorhexis in eyes with phacomorphic glaucoma. J Cataract Refract Surg. 1998;24:882-4.

2. Kara-Junior N, de Santhiago MR, Kawakami A, Carricondo P, Hida WT. Mini-rhexis for white intumescent cataracts. Clinics (Sao Paulo). 2009;64:309-12

2. Bissen-Miyajima H. Ophthalmic viscosurgical devices. Curr Opin Ophthalmol. 2008;19:50-4.

Editors’ note: Dr. Teng is affi liated with the Einhorn Clinical Research Center, New York Eye and Ear Infi rmary, New York, NY, USA; New York Medical College, Valhalla, NY, USA; and New York University School of Medicine, New York, NY, USA. He has no fi nancial interests related to this article.

Contact informationTeng: [email protected]

Preventing - from page 22

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Taking the spin out of toric rotation: Part 1by Steven G. Safran, MD

I consulted a panel of

Stephen Lane, MD,

Michael Wong, MD,

Jeff Horn, MD, and Lisa

Arbisser, MD, to ask what they

would do for this patient’s left eye

given the problems he had with

toric IOL rotation twice in his right

eye after cataract surgery.

Figure 3 is an image of the OD

that had cataract surgery 4 years

ago. Note the advanced glistenings

and the rhexis that extends beyond

the optic nasally.

Dr. Wong (Princeton Eye

Group, Princeton, NJ, USA) said,

“In this case, high myopia is

a predisposing factor for toric

malrotation. The history of the fi rst

eye does not make clear whether

the malrotation went to the same

axis each time. Nevertheless, a large

bag diameter that is greater than

the IOL diameter is the likely cause.

Some surgeons have suggested

inserting capsular tension rings

(CTRs) in these cases as it evenly

distributes the forces at the equator,

to make the bag taut so the capsular

leaves come in closer proximity,

and to simply put material in the

fornices to increase rotational

friction. On the other hand, if

the effect of the CTR is to further

stretch the edge of the bag beyond

the haptics, it is conceivable to

make matters worse. I am not aware

of a study that has tackled this

issue. I would be less aggressive

than usual in vacuuming the

underside of the anterior capsule

during surgery. In choosing the

toric IOL axis goal, I would give

greater weight to the axis of the

bigger bowtie.”

Dr. Arbisser (adjunct clinical

associate professor, John A. Moran

Eye Center, University of Utah,

Salt Lake City, Utah, USA, and

in private practice, Eye Surgeons

Associates, Iowa and Illinois Quad

Cities) agreed with Dr. Wong

completely but was committed to

Figure 1. Topography, OD, s/p cataract surgery with toric IOL

Figure 2. Topography, OS

the use of a CTR in the second eye.

Like Dr. Wong, she would be less

aggressive with polishing of the

anterior capsule to remove lens

epithelial cells.

“CTR is the only thing to be

done differently, in my opinion.

The CTR should be placed this time

with the toric, and he should be

told that no matter what is done,

short of a two-staged procedure

where the astigmatism is fi xed on

the cornea, there is always a small

chance of required repositioning.

I would be certain to remove all

OVD from the posterior chamber

under the lens, and I would not

aggressively polish LECs off the

anterior capsule to promote an

early sandwich effect for IOL

stability,” Dr. Arbisser said.

Dr. Lane (Associated Eye Care,

St. Paul, Minn., USA) would also

use a toric lens in this case but take

a different approach altogether.

He said, “This patient, in my

opinion, should receive a toric

IOL. … I would perform standard

phacoemulsifi cation, being sure

that the capsulorhexis was well

centered and no larger than

5.0–5.5 mm in diameter. Perhaps

this would be a good indication

for the use of the femtosecond

laser to achieve this. I would then

place the toric IOL in the bag,

prolapse the optic out of the bag

(keeping the haptics in the bag,

i.e., reverse capsule capture) and

then rotate the IOL to the proper

position using either previously

placed ink marks or preferably the

SMI [SensoMotoric Instruments,

Teltow, Germany]. By capturing the

IOL in this way I believe you have

assurance the lens will not rotate

or come out of position; it has

essentially been locked in place and

return visits to the OR are avoided.

Depending upon the power of the

IOL (I assume it will be a relatively

low power IOL due to the axial

length), it could be adjusted 0.2-0.5

D (or not at all if a low enough

power) to account for the slightly

anterior position of the IOL.”

Dr. Lane’s novel approach of

anterior optic capture would likely

be successful but may make some

surgeons who have seen pigment

Figure 3 Figure 4Source (all): Steven G. Safran, MD

In the next two columns I’d like

to examine the topic of toric IOL

rotation. We will examine two

patients who had this problem starting

with the presentation of this month’s

case.

The patient is a 48-year-old male

engineer who was a high myope (27

mm eye). He had cataract surgery in

the OD 4 years earlier with a toric IOL

by a highly respected, expert cataract

surgeon. The 11.0 D AcrySof SN60T5

toric lens (Alcon, Fort Worth, Texas,

USA/Hünenberg, Switzerland) that

was placed at that time rotated on its

axis twice in the post-op period and

had to be repositioned two times.

The fi rst repositioning was done

14 days after his cataract surgery,

but the lens rotated again, and the

second repositioning was done 23

days later and ended up with a stable

outcome at the proper axis.

The patient contacted me by email

asking if I’d be willing to see him for

a consultation and to perform cataract

surgery in the second eye. He lived

3,000 miles away but was willing

to travel. His goal was to avoid the

repositionings that were required after

his fi rst eye surgery, as he found these

to be more stressful than the initial

cataract surgery.

The right eye (dominant eye) has

an AcrySof toric in proper position,

3-4+ glistenings, and a best corrected

vision of 20/20 with a –0.75–0.75X

107 refraction. Uncorrected vision was

20/50.

The non-dominant left eye had a dense

NS cataract with 20/200 best corrected

vision. This eye was also 27 mm and, like

the fi rst eye, had 2.37 D of topographic

astigmatism with a corneal topography

that was a bit “funny” with slightly

non-orthogonal astigmatism that

made me nervous about doing LRIs or

LASIK (Figures 1 and 2).


ts



Haike GUO, MD, PhDGuangdong Provincial People’s HospitalZhongshan 2 Road, Guangzhou, ChinaTel. no. +86-020-83844380Fax no. [email protected]

Continuously developing IOL technologies allow surgeons to consider corneal astigmatism in planning the cataract postoperative refraction. In recent years, toric IOLs have proved effective in the correction of corneal

astigmatism following cataract surgery. But toric rotation postoperatively has been found frequently, and it is a serious problem especially in high myopes.

At the Guangdong Eye Institute, we usually use toric IOLs and capsular tension ring (CTR) implantation for the correction of corneal astigmatism in high myopia.

In-the-bag IOL dislocation is thought to depend upon zonular instability, for example in eyes with traumatic injuries or pseudoexfoliation syndrome, after vitrectomy, in patients with Marfan syndrome, and in eyes with high myopia. The CTR has been found to provide stabilization of the capsular bag and IOL during and after cataract surgery in cases of zonular instability and large capsular bag.

In our clinical observation, the use of toric IOLs and CTRs could provide rotational stability and IOL centration in large capsular bags because of the fi nal refractive effect.

As discussed, reverse optic capture (ROC) is another way of preventing toric rotation for high myopes. The optic capture was fi rst described by Neuhann as rhexis-fi xation lens in 1991 (a three-piece posterior chamber IOL was placed in the ciliary sulcus and then the optic was depressed posteriorly beneath the rim of the anterior continuous curvilinear capsulorhexis to achieve IOL stability). In contrast, ROC is achieved by capture of the optic anteriorly through the anterior capsulorhexis opening (haptics in the bag, optic anterior to rhexis). Now, it is often used in cases of incomplete or insuffi cient capsule support. Although ROC has been used for many other purposes and its technique is detailed, including the use of three-piece or one-piece IOLs, it has not been proved that ROC for toric fi xtion in high myopia is stable and accurate through a precise clinical outcome.

Prevention is more important than treatment for dealing with toric rotation. But for patients having toric rotation, waiting 4-6 weeks for capsular contraction and then performing the repositioning is a good way to solve the problem.

In a word, I think toric IOL with CTR implantation is an effective method for correcting corneal astigmatism in the course of cataract surgery for patients with high myopia, and technical diffi culties associated with it should not cause problems for an experienced surgeon. In addition, although creating individually adjusted IOLs is associated with the cost of the procedure, it is another way to solve the problem and may come true easily in the future.

Editors’ note: Prof. Guo is a consultant for Alcon, but has no fi nancial interests related to his comments.

Views from Asia-Pacifi cHadi PRAKOSO, MDKlinik Mata NusantaraJl. Paus Dalam C-16, Rawamangun, Jakarta 13220 IndonesiaTel. no. [email protected]

Looking at Dr Safran’s cases, I would like to share my personal experience. I

have had four post-op rotation cases (one was a high myope) out of my over

350 toric patients. All these cases occurred in the fi rst week after surgery.

When I reexamined the videos of those surgeries, I noticed that I had not removed

the OVD meticulously from behind the IOL and the equator of the capsular bag.

So, it is clear for me that residual OVD in the bag makes the bag so slippery that it

prevents the IOL from staying in its proper position.

When I repositioned my cases, I used cohesive OVD to release the capsular bag

from its attachment to the IOL because it is easier to remove all OVD from the bag

without leaving any residual OVD compared to using dispersive OVD such as Viscoat

after repositioning is completed. All repositions were performed 2-5 weeks after

the fi rst surgery, and all IOLs remained stable after surgery in the desired position.

I do not agree that leaving the LECs on the anterior capsule may facilitate adhesion

of the IOL to the capsular back since all post-op rotation always occurs within the

fi rst post-op week before LECs undergo fi broblastic transformation. Also, I do

not think that it is necessary to perform ROC when you restore the IOL position,

because this is not an easy procedure on single-piece IOLs and on the other hand

the potential risk of pigment dispersion and glaucoma may persist.

A CTR with a 14-mm diameter in a large capsular bag as in high myopic eyes seems

a rational way to avoid post-op rotation. The CTR will stretch the capsular bag and

makes both the anterior and posterior capsule stay much closer to each other,

which will clamp the haptics of the lens. Especially in a post-vitrectomy eye, the

CTR will keep the capsular bag in its normal shape and secure the position of the

IOL. Unfortunately, I do not have any experience with CTRs in such a case.

Finally, I believe that the most important thing to prevent post-op rotation of a toric

IOL is a thorough OVD wash from behind the IOL and equator of the capsular bag.

Editors’ note: Dr. Prakoso has no fi nancial interests related to his comments.

dispersion due to interaction of the

iris and one-piece AcrySof lenses

a bit nervous, whether or not they

have actual cause to be in this

proposed situation.

Dr. Horn (Vision for Life,

Nashville, Tenn., USA) would take a

more conventional approach.

“Anecdotally, there does seem

to be a higher incidence of rotation

in long eyes with presumably

large capsular bags,” he said. “In

these cases, the lens has been

reported to rotate again even after

repositioning, and in at least some

of these cases, the lens seems

to rotate to the same position,

implying that there is a ‘home’ in

these particular eyes, which would

suggest the bags are not round,

but oval. So there may be place for

a CTR, which would presumably

‘round out’ the capsular bag,

reducing rotation if the lens were

initially oriented in the long axis or

diameter of the bag. Other things

regarding surgical technique may

be important to prevent rotation,


Taking - from page 25



or

32



Taking the spin out of toric rotation: Part 2by Steven G. Safran, MD

than the 13.0-mm haptic diameter

(such as with a high myope), if

there has been a disruption of

the zonular apparatus so that the

bag is not round (the IOL will

tend to drift toward the greatest

diameter), lack of evacuation of the

VED (countering the effect of the

tackiness of the acrylic material

or laying down of fi bronectin),

or zonular variation or anterior

capsular fi brosis that diminishes

the fi brosis or ‘shrink wrapping’ of

the capsular leaves (a case for not

vacuuming all of the sub-anterior

capsular cells).

“This case is a high myope, but

in addition, he had a vitrectomy.

This surgery increases the risk of

zonular disruption, making the bag

irregular. In this case, insertion of a

CTR makes sense.

“In my experience, sometimes

practice does not follow theory.

There are unexplained rotations

and inexplicable refractive

surprises. I then turn to corneal

laser vision correction to erase the

residual refractive error when not

contraindicated.”

Lisa Arbisser, MD, adjunct

clinical associate professor, John

A. Moran Eye Center, University

of Utah, Salt Lake City, Utah,

USA, and in private practice, Eye

Surgeons Associates, Iowa and

Illinois Quad Cities, would also

implant a CTR here. “Since the

CCC is on the optic, you can open

the bag and insert a CTR and rotate

the lens.”

Jeff Horn, MD, Vision for

Life, Nashville, Tenn., USA, on the

other hand, would simply wait a

bit, rotate and only use a CTR to

facilitate rotation if it were proving

to be diffi cult otherwise. “In this

patient whose lens has rotated,

I would wait at least three more

weeks for the capsule to begin to

contract. There is no rush. I would

then return to the OR, viscodissect

the lens with a dispersive OVD, and

rotate it to the proper axis. If there

were any diffi culty in rotating it,

I would implant a CTR, and then

rotation will be easy.”

Stephen Lane, MD, medical

director, Associated Eye Care, St.

Paul, Minn., USA, and adjunct

professor of ophthalmology,

Michael Wong, MD,

Princeton Eye Group,

Princeton, NJ, USA,

commented, “Toric

IOL rotational stability derives

from at least fi ve factors: rotational

friction of the haptics at the

equator of the capsular bag, the

square edge of the profi le of the

IOL, the tackiness of the acrylic

material, the adhesiveness of

fi bronectin between the IOL and

bag, and later the fi brosis of the

capsular leaves around the haptics.

“Conversely, postoperative

rotation of the IOL can occur if

the diameter of the bag is larger

Figure 1. Post-op at one week shows the lens at 67 degrees.

Figure 2. IOL in proper position post-opSource: Steven G. Safran, MD

This is the second case in a two-

part series looking at the subject

of toric rotation and how to

manage it. This is a young, male, high

myope (53 years old) with a history of

macula-off retinal detachment (RD)

repair in the right eye who presented

with rather impressive cataracts in

both eyes. I did cataract surgery

in the left eye fi rst with a standard

monofocal IOL, and the patient did

very well with a 20/20 uncorrected

outcome. The OD had 1.75 diopters

of cornea astigmatism with the steep

axis at 100 degrees and is 27.35 mm

so an 11 diopter T4 was chosen with

a surprisingly good post-op day 1

visual outcome—20/40+ uncorrected.

This is a bit better than expected

because of the history of a macula-off

detachment.

At one week post-op, however, he

noticed that his vision had dropped,

and he presented with uncorrected

20/100-1.

The axis of the lens has rotated

from 100 degrees as planned to 67

degrees. He refracts to about 20/30

with an Rx that includes about 1.5

D of astigmatism. The other eye is

plano = 20/20. He is an avid golfer

and sportsman and would like to avoid

glasses for distance.

What would you do? He’s one week

post-op, and the IOL has rotated 33

degrees off axis, completely negating

the astigmatic benefi t of the toric lens.

Figure 1 is his post-op photo at one

week showing the lens at 67 degrees

when it should be at 100 degrees.

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University of Minnesota, Minn.,

would choose the option of anterior

optic capture to “lock” the lens

in place. “While keratorefractive

procedures could be considered,

they do not solve the basic problem

of the lens being out of position,

and the lens may continue to be

unstable and rotate down the line.

The photograph shows a well-

positioned toric IOL in the bag

with good overlap of the anterior

capsule over the optic (at least for

the 270 degrees or so that I can

see). After viscodissecting the IOL

free, I would prolapse the optic in

front of the rhexis (reverse capsule

capture) and rotate it to the proper

position on the steep axis. This can

be done quite atraumatically with

minimal risk.”

Because I have no personal

experience with anterior optic

capture, I was a bit uncomfortable

with the idea of purposefully

putting part of a single-piece

AcrySof implant (Alcon, Fort


Switzerland) anterior to the rhexis

where it could potentially contact

the iris. I asked about experience

with reverse optic capture (ROC)

using the single-piece AcrySof

platform on the ASCRS chat board

and got this response from Jason

Jones, MD, medical director, Jones

Eye Clinic, Sioux City, Iowa.

“ROC is a capsule fi xation

technique where the haptics of the

IOL are posterior to the anterior

capsule and the optic is brought

forward (captured) by the intact

CCC. Several anatomic elements

must be respected here. The CCC

must be intact, smaller than the

optic, and well centered. The

zonules must be stable. And the

CCC must be free of any vitreous

(if the PC has been breached).

Ideally the confi guration of the iris

relative to the capsule should be

assessed; I don’t have any numbers

to recommend here, but there

should be good clearance to avoid

iris-optic contact. Given that the

cataract has been removed and the

IOL occupies much less space, I feel

it is reasonable to assume most (not

all) eyes will avoid such contact.

In the case of repositioning a toric

with ROC, this can and should

be considered. Once the lens is

rotated into position then the

optic can be brought forward to

obtain capture. … Now, I have

not had an opportunity to use

ROC for a misbehaving toric lens.

But I have implanted a series of

AcrySof single-piece acrylic IOLs

using ROC. In these cases the

PC was damaged during primary

surgery, and I elected to use this

technique. All of my patients have

done very well with clear visual

pathways, no UGH syndrome, no

RD, no decentration, and with

up to four years or more follow-

up in select cases. This is not

sulcus fi xation, and the issues that

AcrySof SPA IOLs in the sulcus

have encountered should not be

confl ated with ROC.”

Dr. Jones’ experience with this

technique should be comforting

to those who may consider it. In a

follow-up email, Dr. Lane did add

that he has done ROC “twice with

good results and no iris chafe.” I

do have the personal experience

of having treated six cases of

pseudophakic reverse pupillary

block that caused contact between

the iris and IOL leading to iris

chafi ng and pigment dispersion.

I reported and discussed this

phenomenon in the ASGR column

of the January 2012 issue of

EyeWorld, “Reversal of misfortune.”

All patients were vitrectomized

high myopes (as is the case here)

so I believe that if one wishes to

consider ROC in a vitrectomized

high myope, one should also

consider placing a peripheral

iridotomy to prevent the possibility

of reverse pupillary block

occurring, which could lead to the

iris being pushed back against the

optic, leading to chafi ng.

In this case I chose to simply

wait fi ve weeks and reposition

the lens. My own experience is

that if you reposition the lens

immediately, it is very likely to

rotate again. If, on the other hand,

you wait a few weeks for some

fi brosis to occur, the bag will shrink

wrap a bit around the lens, and

the lens will not rotate a second

time. Although a CTR could have

been used, I discussed the option

with the patient who wished not to

have one placed unless I felt it was

absolutely necessary. In this case I

did not feel that it was so we chose

not to use it. The patient ended up

with a 20/30 fi nal outcome and no

repeat rotation (Figure 2). One does

not want to wait so long that the

haptics become so strongly fi brosed

in place that they are impossible to

free up but long enough that there

is some shrink wrapping of the bag

around the lens so that the lens is

not likely to rotate a second time.

Although we don’t know the exact

timeframe for this, it is likely that

waiting fi ve to six weeks post-op

from the original cataract surgery is

a pretty safe play.

One tip is that if you know

the axis the lens is at, you don’t

need to mark the patient sitting

up. For example, in this case the

lens was measured at an axis of 67

degrees at the slit lamp, so I simply

made a mark 33 degrees in the

counterclockwise direction under

the surgical microscope knowing

that this would be exactly 100

degrees and then I rotated the lens

to this point. I like to use a fl at tip

LASIK cannula (Katena K7-5106,

Denville, NJ, USA) to get under

the edge of the anterior capsule

and initiate viscoelastic dissection.

When you reopen the bag there

is no need to “hyperinfl ate” with

viscoelastic but rather to reopen

just enough to easily facilitate

rotation. The capsular bag exhibits

a slightly different stiffer feel at

six weeks out then it does at the

time of initial cataract surgery

due to fi brosis, and I believe this

is what prevents the lens from

rotating again. After rotation the

viscoelastic is removed and the case

is completed.

Again, the CTR turned out not

to be necessary. If I were to treat

a patient who was not willing to

consider waiting 4 to 6 weeks for

a rotation then I would defi nitely

use a CTR, but if you can wait a

bit to do the repositioning, a CTR

is probably not needed. If this

lens were to rotate again, I would

consider adding a CTR, and fi nally

if it rotated a third time, reverse

optic capture with a laser iridotomy

could be considered as a fi nal

option. EWAP

Editors’ note: Drs. Arbisser, Jones, Lane, and Wong have no fi nancial interests related to this article. Dr. Safran has fi nancial interests with Bausch + Lomb.

Contact information

Arbisser: [email protected]

Horn: [email protected]

Jones: [email protected]

Lane: [email protected]

Safran: [email protected]

Wong: [email protected]



The business side of femto for cataractby Michelle Dalton EyeWorld Contributing Writer

Effi cacy and safety issues

aside, practices debating

how to integrate a femto-

second laser and when to

use it should read on

When evaluating

whether or not

to purchase a

femtosecond

laser for refractive cataract surgery,

the question is not whether or not

the technology is viable, but how to

bring a very expensive and space-

consuming piece of equipment into

the surgical area without disrupting

patient workfl ow. Leading

authorities tell EyeWorld how they

went about it.

Physical placementPhysically smaller practices—those

with one or two ORs—that have

dedicated refractive and cataract

suites have an advantage over a

general teaching hospital where the

OR is used by various specialties,

said Kevin M. Miller, MD,

Kolokotrones Professor of Clinical

Ophthalmology, Jules Stein Eye

Institute, Los Angeles, Calif., USA.

Ambulatory surgery centers (ASCs)

with three or four rooms, however,

have a harder situation “because

you might have two doctors doing

cataract surgery on a given day,

and you’re probably not going to

buy one femto laser for each room,”

Dr. Miller said, adding some bigger

facilities are “just fi nding a closet

where they can place it.”

The dilemma for ASCs is that

most haven’t been built with

enough physical space to house

the laser and may end up placing

it on another fl oor altogether,

said Robert P. Rivera, MD, in

private practice, Hoopes Vision,

Draper, Utah, USA. His group was

already scheduled to move into a

new facility at the end of last year,

so they reconfi gured the space to

accommodate the two femtosecond

lasers the ASC uses into their own

dedicated room.

For Robert J. Weinstock, MD, in

private practice, the Eye Institute

of West Florida, Largo, Fla., USA,

there were already four ORs and a

good amount of pre-op and post-op

space, “but what we didn’t have is

a lot of ‘extra procedures’ room. In

one small room we have a YAG laser

and an argon laser, but no room to

house more.” The group weighed

several options, including “stealing”

a conference room, or taking some

space away from the kitchen and

other administrative areas. They

decided to place the laser in one of

the ORs and drop down to three

rooms for intraocular surgery.

At the Center for Sight, Sarasota,

Fla., William Soscia, MD, said

four of the surgeons are cataract

specialists, and the entire ASC

is “very high volume”. The

group spent almost two years

evaluating how to incorporate the

technology into the available space

and ultimately opted to build a

separate room, complete with an

observation area for family to watch

while staff members narrate the

entire femtosecond aspect of the

procedure.

Dr. Miller said “moving 80- and

90-year-olds around is no simple

matter,” but at Jules Stein the only

place to put the femto laser was on

a different fl oor from the surgical

suite, and that with 10 surgeons

vying to use the laser, “it’s going to

be a total nightmare.”

Impacting the workfl owThe Catalys (OptiMedica,

Sunnyvale, Calif., USA) is the only

one of the devices where patients

can have the femto portion done

on the same bed as their cataract

removal, Dr. Rivera said. From a

patient perspective, that’s the least

disruptive, he said, but not all

machines are capable of that just

yet.

“Ergonomically, we had to decide

what would make the most sense,”

Dr. Rivera said. “The downside to

that scenario is that it does commit

that room to only the surgeons

who are going to use the Catalys.

That only works in a situation

with dedicated anterior segment

surgeons.”

The logistics of scheduling several

surgeons when the femto resides

alongside a phaco machine is

daunting, Dr. Miller said, but it’s

equally diffi cult when the femto is

in a separate location.

“It’s now going to take a procedure

that takes, say, 20 to 25 minutes in

an average person’s hands, or 10

minutes for somebody who’s really

fast, and make it at least twice as

long, if not three times as long, if

the laser is outside the room,” Dr.

Miller said. With reimbursement

rates declining, losing time on one

patient because of logistics can be

economically devastating.

Workfl ow can be diffi cult in very

high volume practices, Dr. Soscia

said. “Before we had the LensAR

[Orlando, Fla.] in our practice, we

analyzed how to incorporate it—we

started focus groups from patients

to gauge interest, we evaluated

where to physically place it, we

looked at staffi ng issues, and then

we tackled how we were going to

market this to our patient base.”

Dr. Weinstock’s group, “a relatively

high-effi ciency, high-volume center,

where we like to do somewhere

At Hoopes Vision, two different femtosecond lasers reside in a previously underused OR.

Source: Robert Rivera, MD




e

y

e

y

er,

32



between seven to eight cases per

hour at least,” realized positioning

the femto in its own room “would

improve the effi ciency of patient

fl ow and keep the surgeon from

being idle.” With almost 50% of

their patients undergoing limbal

relaxing incisions, toric lenses,

or premium IOLs, the center has

turned one OR into an advanced

cataract room complete with

intraoperative aberrometry and 3D

guidance software. The patients

move directly into this room after

their femtosecond laser treatment

in another room. There is also a

standard OR for traditional cataract

surgery.

“We made the decision to take

one of our remaining two ORs and

put both the LenSx [Alcon, Fort


Switzerland] and the Catalyst in

there,” Dr. Rivera said.

Sharing responsibilitiesSurgical centers will need to

evaluate not only patient workfl ow,

but also surgeon workfl ow. Dr.

Soscia said in the previous three

months, he’s probably performed

“over 600 femtosecond cases.” He

volunteered to be the ASC’s femto

expert and has reorganized his

schedule so that three days a week

he’s doing femto for his partners,

and one day a week he’s doing the

femto for his own patients.

“With this setup, I can do about

eight laser cases an hour, therefore

allowing the cataract surgeons

to perform the same number of

cases as they were prior to the

femtosecond laser,” Dr. Soscia said.

Dr. Miller will likely have each

surgeon do his or her own femto

cases initially, “and then we’ll have

to fi gure out what makes the most

sense. We’ll have a technician be

the femto laser technician just like

we have in our laser practice center.

It may even be the same person.”

Eventually, he predicts fellows will

do part of the procedure.

Dr. Weinstock split the

responsibilities with his partners—

one day they each do only the

femto, the next they do only the

cataract surgery aspects. Dr. Rivera

has not transitioned into this model

yet, but his new facility will allow

them to do so.

“If I have 20 patients scheduled for

cataract surgery on an afternoon,

at least 50% of those are getting

femto,” Dr. Weinstock said. “So

that’s the equivalent of doing 30

procedures, not 20. [You have

to] take into account bringing

the patient into the room,

programming the laser, getting

the patient in position, doing the

procedure, and on and on. This

takes just as long as the cataract

surgery itself. So far, it’s working

great to divide the tasks with two

surgeons. We can each keep our

focus. And if you’re the guy who’s

just doing lasers, you’re 100%

focused on just doing the laser.”

For the other surgeons? “They’ve

got 50% of the procedure already

done,” Dr. Soscia said. “Me? I’m just

in the zone.” EWAP

Editors’ note: Drs. Miller, Rivera, and

Soscia have no fi nancial interests

related to this article. Dr. Weinstock

has fi nancial interests with Alcon and

Bausch + Lomb (Rochester, NY, USA).

Contact information

Miller: 310-206-9951, [email protected]

Rivera: 801-568-0200, [email protected]

Soscia: 941-806-9784, [email protected]

Weinstock: 727-244-1958, [email protected]

such as evacuating all the OVD

from behind the lens. Some have

suggested that not polishing or

vacuuming the underside of the

anterior capsule increases the

‘stickiness’ of the lens. I don’t

believe this to be true.

“This patient is highly sensitive

to a less-than-spectacular result

and is willing to travel great

distances to achieve that. First, his

astigmatism clearly needs to be

managed surgically. Because of the

slight skewing of the astigmatism

on topography, and because of

my confi dence in the toric lens,

I would still implant the toric.

But in order to reduce the odds

the lens rotated, I would implant

a CTR prophylactically prior to

implantation of the lens.”

I agree with Dr. Horn here, and

this is basically the approach that

I took. I have seen or consulted in

a handful of cases of toric rotation,

and all have been in high myopes

who rotated within the fi rst

week or so. Since rotation occurs

before the LECs remaining on the

anterior capsule have undergone

any fi broblastic transformation

and prior to any resultant bag

contracture, I see no benefi t to

purposefully leaving LECs behind.

They will not be able to prevent

the early rotation that we typically

see in these cases, although later

on they will certainly cause fi brotic

changes that will “lock things in

place.” Within the fi rst week or

so, I don’t believe the presence

of LECs helps and, in fact, may

prevent some of the tacky adhesion

between the optic and the capsule

that we typically see with the

AcrySof material. Anyone who

has tried to rotate a toric lens

after removing all the viscoelastic

knows that there is an immediate

adhesion between the tacky

AcrySof material and the capsule

that is somewhat unique to this

material. To rotate the lens without

stressing the capsule, one often

needs either additional viscoelastic

or an infusion line to dilate the

bag. As Dr. Horn stated, I believe

that in high myopes the bag may

be a bit too large for the lens and it

may not be perfectly round, which

creates a “preferred axis” that the

lens may gravitate toward. I believe

that the use of a CTR will both

round out the bag and make the

equator of the bag slightly smaller,

creating a frictional resistance to

early rotation. If the lens does not

rotate immediately (within the fi rst

10 days or so), then it is extremely

unlikely to rotate at all.

In this case I did choose to use

an 11 D T5 toric lens (Alcon) to

correct astigmatism and targeted

a –0.25 spherical outcome for

better distance vision as per the

patient’s request. I used my normal

surgical approach, creating a

centered round rhexis (effectively

achieved without the benefi t of a

femtosecond laser) that covered

the optic 360 degrees followed by

meticulous removal of LECs with

a Singer Sweep (Epsilon Surgical,

Ontario, Calif., USA). I did choose

to place a CTR with the hope that

this would prevent rotation and

then removed all viscoelastic from

behind the lens and took extra

precaution to press the optic

down against the posterior

capsule at the end of the case

to create adhesion against the

posterior capsule. The patient did

very well with no IOL rotation

post-op and a –0.25 refractive

outcome with 20/20 uncorrected

distance vision. He was very happy

with this. Figure 4 is an image of

the eye 1 month post-op.

It does appear that the use of

the CTR inhibited the rotation of

the lens in this patient. I do think

that it is reasonable to consider the

primary use of a CTR for toric IOL

cases at high risk for rotation. All of

the cases of rotation I’ve seen so far

have been relatively young, highly

myopic males, so in a patient fi tting

this demographic, especially with a

history of rotation in the fi rst eye, I

would certainly consider using this

approach again. EWAP

Contact informationArbisser: [email protected]: [email protected]: [email protected]: [email protected]

Taking - from page 26The business - from page 30


33EWAP REFRACTIVE March 2013

Mysterious infection after LASIK has lessons for allby Matt Young EyeWorld Contributing Writerr

Refer patients early on

when an infection is identi-

fi ed and is non-responsive

to antibiotics

Not all refractive surgeons

would consider themselves

to be corneal specialists. Yet

a recent case in the Middle

East should give more reasons for

refractive surgeons worldwide to be

aware of serious corneal problems

that can arise from minimally

invasive surgery and to be prepared

for them at any time.

Infection gone awryNada S. Jabbur, MD,

Clemenceau Medical Center, Beirut,

Lebanon, and clinical adjunct

associate professor, American

University of Beirut, was recently

referred a case of a young female

myope who underwent LASIK

bilaterally about a month earlier.

The patient was told everything

was fi ne shortly after her procedure.

On post-op day 1, she began

experiencing irritation and

blurriness in her right eye. The left

eye was doing well at 20/20.

The right eye appeared to have

a corneal infection in the LASIK

fl ap, which was not improving. She

was treated with a broad spectrum

of antibiotics while cultures

were taken and sent to the lab to

investigate for bacteria and fungi.

“Cultures done initially did

not reveal any fungi,” Dr. Jabbur

said. A week later, the fl ap was

amputated because of the infection

progressing and melting the fl ap.

The patient was also treated for

possible Acanthamoeba due to her

severe pain and poor response to

antibacterials. Four weeks after

the LASIK surgery, the patient was

referred to Dr. Jabbur.

“From limbus to limbus,

the cornea was an abscess,” Dr.

Jabbur said. “It was a mix of pus

and necrotic tissue with a central

descemetocele. Clinically, we

could not be sure if the infection

had spread beyond the anterior

segment, but ultrasonography

showed that the posterior globe was

probably intact.

“We took the patient to the

operating theater and dissected

away what was left of the cornea

together with a rim of clean sclera

where we could suture the donor

cornea with its trimmed scleral

rim,” Dr. Jabbur continued. The

cornea was stuck to the anterior

lens capsule; the latter was

removed, and the lens material

was aspirated. No intraocular lens

was placed at this time due to the

infection. A donor cornea with a

scleral rim was sutured in place.

Post-op, the patient slowly

improved. She required a second

surgery to clean residual cortical

material. “She remains aphakic and

has been able to see 20/30 with

correction,” Dr. Jabbur said. “Her

retina was unaffected. She will

need further surgery to clean an

opacifi ed posterior capsule as well

as a secondary IOL.”

After sending the patient’s

cornea for culture and pathology,

the cultures yielded a species of

Fusarium found deep in the tissue.

Missed red fl agsDr. Jabbur said there were

important warning signs that were

missed in this case.

“When an infection is not

responsive to antibacterials, one

needs to suspect fungal infection.

When physicians take cultures

they need to take them properly,

including normal and abnormal

tissue, not just necrotic tissue,” Dr.

Jabbur said. Also “inform the lab to

keep the plates for a longer period

of time if you are suspecting fungal

infection. Universities are used

to that more than settings where

culture plates are sent to an outside

facility.”

In this case, the fungal

infection was not diagnosed early

on, and it became diffi cult to save

the cornea. “Initially, removing

the fl ap was essential but not

enough. Ideally, the cornea should

have been operated on before the

infection reached the limbus,” Dr.

Jabbur said. “The chance of a graft

rejection is more likely when there

is a scleral rim that is transplanted

and when the graft is larger in

size.”

Dr. Jabbur said that if the

patient’s problem is beyond

the capacity of a general

ophthalmologist, it should be

referred as soon as possible to a

cornea specialist. “This case could

have happened anywhere in the

world, and prompt management

is key and alters the prognosis

dramatically.” EWAP

Editors’ note: Dr. Jabbur has no fi nancial interests related to this article.

Contact information

Jabbur: +961 1 372888 ext. 1133, [email protected]

Limbus-to-limbus corneal abscess with central descemetocele

Appearance of globe 2 weeks after corneoscleral graft

Cultures of the cornea grew Fusarium speciesSource (all): Nada S. Jabbur, MD

33-42_EW REAFTIVE.indd 3333-42_EW REAFTIVE.indd 33 22/03/2013 16:3422/03/2013 16:34

34 EWAP REFRACTIVE March 2013

Presbyond Laser Blended Vision: Another approach to presbyopiaby Dan Z. Reinstein, MD

The ideal solution for

correcting presbyopia

would be to restore

accommodation, however,

no procedure up to now has been

proven to reverse presbyopia

and restore the natural focusing

mechanism of the eye. While there

is ongoing research on techniques

to achieve this, clinical applications

of these techniques will probably

not be available for another 10-20

years. Because of our inability to

restore accommodation, current

treatments for presbyopia rely on

splitting the refractive power for

distance and near either within

the same eye (multifocality)

or between eyes (monovision),

but all treatments require some

compromise from the patient.

The challenge for such

treatment options is to achieve

good binocular vision at far,

intermediate, and near distances

while also maintaining optical

quality, contrast sensitivity, night

vision, stereo acuity, and as a bonus

the procedure should be reversible.

This was the goal that we set

when developing Presbyond Laser

Blended Vision with Carl Zeiss

Meditec (Jena, Germany), and our

approach was to take advantage of

the natural mechanisms within our

optical system and minimize the

need for the patient to adapt.

All multifocal approaches

require the patient to adjust to the

unnatural situation of having to

differentiate between two images

in the same eye, so it is no surprise

that these procedures are associated

with loss of CDVA, contrast

sensitivity, and night vision

disturbances. There have been

signifi cant improvements over the

years; however, multifocality will

always rely on the patient’s ability

to adapt to this new and unnatural

intraocular rivalry. Multifocal

treatments are also usually limited

to a small range of refractive error

(usually low hyperopic patients).

The well-established principles

of contact lens monovision have

been used in laser refractive

surgery; however, many of

the limitations of contact lens

monovision also affected laser

Spherical aberration diagramSource: Dan Z. Reinstein, MD

Views from Asia-Pacifi cPOR Yong Ming, MBBS, FRCS, MMed, MRCOphthConsultant Eye Surgeon, Jerry Tan Eye Surgery& Jerry TAN, MBBS, FRCS, FRCOphth, FAMSConsultant Eye Surgeon, Jerry Tan Eye SurgeryCamden Medical Centre,1 Orchard Boulevard #10-06Singapore 248649Tel. no. +65-6738-8122Fax no. [email protected]

Presbyond as a concept is attractive in potentially

enhancing the benefi ts while moderating the

cons of standard monovision. However, a number

of aspects of this treatment bear consideration.

Theoretically, there is no doubt that spherical aberration

(SA) or even coma and astigmatism can improve an

eye’s depth of fi eld, but at the expense of some loss of visual quality. Indeed,

as Dr. Reinstein mentions, beyond a certain amount of SA the visual cortex no

longer compensates and considerable disturbances such as haloes and loss of

contrast surface. In real life, we have all seen changes of corneal topography

as an eye heals after laser refractive surgery, originating from factors such as

epithelial remodeling. As such, attempting to maximize depth of fi eld to 1.50 D by

fi ltering SA while avoiding side effects involves negotiating a fi ne line which can

easily be crossed by individual healing responses.

Presbyopic patients are also older than the average LASIK patient, and lenticular

changes are not insignifi cant. The aging lens is associated with increasing

SA with time, so even if Presbyond manages to hit the target on the cornea, one

cannot be certain how long it will be before the combined corneal and lenticular

aberrations cause noticeable visual disturbances.

The effects of any optical aberration depend greatly on pupil size, and it is intriguing

that pupillometry is not mentioned as a factor considered in the generation of the

ablation profi le. Unless Presbyond can tailor the SA to suit the range of pupil sizes

seen in different patients, the hoped for effects may not materialize. It is also

possible that a patient has large scotopic pupils in the dark which magnify the

visual disturbance caused by the induced SA.

According to the diagram accompanying this article, it appears that positive

spherical aberration is induced by the Presbyond ablation profi le, causing

peripheral rays of light striking the lens periphery to be focused before more

central rays. This is reminiscent of night myopia, resulting from scotopic mydriasis

in the presence of positive SA. It would be the opposite of what is required for

presbyopia, since during close work the pupil becomes miotic. Perhaps a small

amount of negative, rather than positive, SA may be helpful in the presence of a

bias toward slightly more myopic undercorrection.

We look forward to studies comparing standard monovision and Presbyond Laser

Blended Vision, to quantify its benefi ts as well as potential for visual side effects.

Editors’ note: Drs. Por and Tan have no fi nancial interests related to their comments.




// ReLEx MADE BY CARL ZEISS

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Michael LAWLESS, MDMedical Director, Vision Eye Institute4/270 Victoria Ave., Chatswood, NSW 2067 AustraliaTel. no. [email protected]

Dr. Reinstein is to be congratulated for exploring the use of spherical aberration

to enhance depth of focus in presbyopic patients. The same thoughts have

occurred to those using an IOL approach to presbyopia with lenses now

being trialled which increase spherical aberration to provide a similar effect.

The problem with analyzing the data provided is that the age of the patients would

have signifi cant bearing on the results presented, but it is not clear from the article

how age would have impacted Dr. Reinstein’s excellent results.

All good things come at a cost. Generally, in the normal untouched eye, the cornea has

positive spherical aberration which is matched by the negative spherical aberration of

the lens, resulting in a more or less neutral state. Of course there is a range through

the population in both the degree of corneal and lens spherical aberration. We also

know that the natural lens changes from negative to positive spherical aberration

with age and this is the very population in which a presbyopia treatment would be

required. This is one reason why the quality of vision under mesopic and scotopic

conditions declines with age. The impact of spherical aberration on visual function is

pupil dependent. So there are many variables to consider when attempting to change

the spherical aberration profi le of an individual patient.

To induce more spherical aberration on the cornea to enhance depth of focus has to

unquestionably alter the quality of vision, particularly night vision, which is one of

the reasons that LASIK excimer laser profi les moved from conventional to optimized

and wavefront guided, based on a knowledge of higher order aberrations and their

effect on the visual system.

This is an interesting approach and is likely to be helpful in a small way to enhance

presbyopic treatments, but I think we need data to support these optimistic fi rst

conclusions and perhaps better targeted treatments based on an individual eye’s

aberration profi le, as Dr. Reinstein rightly points out.

Editors’ note: Dr. Lawless is a consultant for Alcon/LenSx (Fort Worth, Texas, USA/Hünenberg, Switzerland) but has no fi nancial interests related to his comments.

refractive surgery-induced

monovision. These limitations

include loss of fusion due to the

anisometropia between the two

eyes, poor intermediate vision,

poor distance vision in the near

eye, reduced binocular contrast

sensitivity, and reduced (or even

broken) stereoacuity. However,

monovision is based on the

John S. M. CHANG, MDDirector, Guy Hugh Chan Refractive Surgery CentreHong Kong Sanatorium and Hospital8/F Li Shu Pui Block, Phase II2 Village Road, Happy Valley, Hong KongTel. no. +852-2835-8885Fax no. [email protected]

There have been many approaches in corneal refractive surgery to create a

multifocal eye, in order for the eye to see distance, intermediate and near.

Some create a central myopic region, so that when we read and the pupil

constricts, the induced myopia will compensate for the lack of accommodation.

However, if the patient is not satisfi ed with the result, whether this can be safely and

completely reversed is still a matter of discussion and more research. Monovision

works very well in patients who live in a city and do not drive. In our experience,

the success rate is over 95%. However, in countries where patients have to do a

lot of driving, the success rate drops signifi cantly. Recently, Presbyond (Carl Zeiss

Meditec), F-Cat (Allegretto, Alcon), Supracor (Baush+Lomb) all involve some form of

micro-monovision. In Presbyond and F-Cat, negative spherical aberration is induced,

thus increasing the depth of focus. We have had over 5 years of experiences with

the Allegretto F-Cat and have found that it works quite well in myopes below –6

to –7 D and, like the Presbyond, when the patient does not like the monovision or

micro-monovision, it can be easily removed without any loss of vision. Night vision

does not seem to be compromised, however, when the adjustment is pushed too far,

or when the patient’s pupil is too small there tends to be an under-correction. The

disadvantage is that it is still monovision (although the loss of stereovision should

be less) and its effect may not be long lasting because of possible epithelial fi lling

with time.

Editors’ note: Dr. Chang has no fi nancial interests related to his comments.

natural process of binocular fusion

(interocular rivalry as opposed

to the unnatural intraocular

rivalry experienced in multifocal

procedures), and recent studies

have demonstrated that many of

these limitations could be avoided

by limiting the anisometropia to

1.25 D or 1.50 D. But this level of

anisometropia does not always give

Views from Asia-Pacifi c

Presbyond - from page 34



e

ACS and the Cornea Society launch CorneaEd

IKS is massive undertaking for ACSIKS is massive undertaking for ACSThe Asia Cornea Society’s Infectious Keratitis Study (ACSIKS) is set to be

a major game changer for the region. “Corneal blindness is big in Asia,”

said Donald Tan, MD, Singapore, current president of the Cornea Society

and the Asia Cornea Society (ACS).

It’s a fair statement, summarizing the signifi cance of the most important

cause of blindness in the region second only to cataract, but it barely

scratches the surface, given the full scope and many nuances of the

problem.

Most corneal disease in the world occurs in Asia, said Prof. Tan. Here, he

said, corneal ulceration is a “silent epidemic.”

But the challenge of corneal blindness in Asia isn’t confi ned to magnitude;

unsurprisingly for the region, huge variations exist from country to country,

such that the problem runs the gamut of the entire spectrum of corneal

infections.

Epidemiological patterns, for one, differ signifi cantly, said Prashant Garg, MD, Hyderabad, India. For instance, whereas studies have identifi ed

contact lens use and ocular surface disease as the major risk factors for

microbial keratitis in a developed region like Hong Kong, trauma is the

most prevalent cause of infection in India, affecting a correspondingly

different age group: Most patients in India, said Dr. Garg, fall in the range

of 20-50 years—the economically productive age group.

Wide variations also exist from country to country in terms of pathogen,

environmental risk factors, the availability of drugs, antibiotic resistance

patterns, access to treatment, and any number of other variables that

have yet to be adequately quantifi ed.

To this end, the ACS has embarked on the ACSIKS, a multicenter,

prospective observational study in 11 study centers in eight major

locations (China, India, Japan, Korea, Philippines, Taiwan, Thailand, and

Singapore).

The study is intended to document the clinical management practices of

doctors all over the region, while also collecting microbiological samples

from recruited cases.

To date, said Prof. Tan, the study has recruited 2,118 cases, with

preliminary data analysis of 1,544 of these cases. Preliminary analysis, he

said, has identifi ed fungal and bacterial pathogens to be the main causes

of infectious keratitis in the region.

Editors’ note: ACSIKS is made possible by the support of Alcon (Fort

Worth, Texas, USA/Hünenberg, Switzerland), Allergan (Irvine, Calif., USA),

Bausch + Lomb (Rochester, NY, USA), and Santen (Napa, Calif., USA).

The Asia Cornea Society (ACS) and Cornea Society have created an

initiative to reach out to young ophthalmologists looking for opportunities

to train in the cornea subspecialty.

“CorneaEd is, quite simply, ‘cornea education,’” said Donald Tan, MD,

Singapore, president of both societies, which, he said, have always had

strong missions for education.

The website is a joint educational initiative of the sister societies,

essentially a registry with links to fellowship programs in the Asia-Pacifi c

and the U.S.

The idea, said Michael Belin, MD, vice president for international

relations, Cornea Society, is to give young ophthalmologists the

opportunity to fi nd programs that will present them with experiences they

might not otherwise have.

This in mind, the two societies hope to select two young ophthalmologists

in the corneal fellowship program of their choice.

Applications will be available on the website in the fi rst quarter of 2013.

For more information and to access the registry, visit www.CorneaEd.org.

the patient enough near vision.

Therefore, with Presbyond Laser

Blended Vision, we incorporated

another natural visual process—

fi ltering of spherical aberration—to

increase the depth of fi eld in each

eye and achieve good binocular

vision at all distances. In an eye

with no spherical aberration, light

is focused to a point, so any forward

or backward movement of the

object will make it instantly go out

of focus. However, if we introduce

some spherical aberration into the

system, there is dissemination of

the focal point, meaning that there

is a wider range of distances where

the focus is equivalent, although

slightly reduced. This of course

applies to the retinal image, but the

image is still perceived as sharply

as if there were no aberrations

due to the natural ability of the

visual cortex to “process” spherical

aberration. This range is the depth

of fi eld and can be demonstrated by

the better-than-expected distance

vision in the near eye (the mean

visual acuity is about 20/45 whereas

20/80 would be expected for a –1.50

D refraction).

This concept is simply an

extension of the eye’s natural state

as everyone has some naturally

occurring spherical aberration, and

the brain is already preprogrammed

to do this fi ltering. If there is

too much spherical aberration,

however, the visual cortex is no

longer able to fully “process” the

spherical aberration and will result

in loss of contrast sensitivity and

other aberration-related quality of

vision symptoms, similar to those

seen after multifocal ablations.

The ideal depth of fi eld in each eye

is 3.00 D, but we have found that

the maximum depth of fi eld that

can be safely induced is 1.50 D.

Therefore, this spherical aberration

method cannot be used to correct

presbyopia by itself but can be

combined with monovision to

improve the range of vision in each

eye.

The increased depth of fi eld in

each eye enables good near vision

to be achieved with a lower degree

of anisometropia than in traditional

monovision, which we refer to as

micromonovision. With Presbyond

Laser Blended Vision, it is possible

to displace the foci between the

eyes and create continuous vision,

from near to intermediate to far.

In essence, this strategy creates

a blend zone of vision between

the two eyes at intermediate

distances meaning that much less

suppression is required and there

is no dissociation between the

eyes. In fact, patients even retain

a functional level of uncorrected

stereoacuity—proving that they

have binocular function.

In Presbyond Laser Blended

Vision, a number of factors

are considered including age,

accommodative amplitude,

pre-op wavefront, tolerance to

anisometropia, and the amount

of refractive error. The software

then combines these factors to

generate an ablation profi le with

the aim of leaving the patient with

an appropriate level of spherical

aberration in order to maximize

the depth of fi eld without

compromising contrast sensitivity,

stereoacuity, or night vision.

At one year after Presbyond

Laser Blended Vision, binocular

UDVA was 20/20 or better and

UNVA was J2 or better in 95% of

136 myopic patients (≤–8.50 D),

77% of 111 hyperopic patients

(≤+5.75 D), and 95% of 148

emmetropic patients (within ±0.88

D). The safety in terms of contrast

sensitivity was the same as for continued on page 43



A scleral approach to presbyopiaby Vanessa Caceres EyeWorld Contributing Writer

Procedure in Phase III FDA trial targets plano presbyopes

The expanding options

for presbyopic patients in

the future may include

the placement of scleral

implants in the eye.

Better known as PresVIEW

(Refocus Group, Dallas), this scleral

spacing procedure for presbyopes

has been around for a while and

continues to undergo review and

follow up as investigators track

patients in the U.S. FDA Phase III

stage of PresVIEW’s clinical trial.

PresVIEW involves the

insertion into the eye of four

polymethylmethacrylate implants

about the size of a small grain

of rice, according to the Refocus

website. Surgeons create tunnels

for the implants in the scleara

with a scleratome, said Karl

G. Stonecipher, MD, medical

director, TLC Laser Eye Centers,

Greensboro, NC, USA. The

scleratome used now is a lighter

weight model than a previous

version. Changes to the scleratome

and the procedure itself have

halved the time it takes to perform

the procedure—from 30 to 40

minutes per eye before to about

20 minutes per eye now, Dr.

Stonecipher said. After the implant

is inserted, U.S.-based surgeons

suture the conjunctiva, while

surgeons in Europe are using tissue

glue, he said.

Patients receive numbing drops

and anti-anxiety medication,

according to the Refocus website.

The patient may have some

soreness and infl ammation a

few days after the procedure,

and it takes a couple of weeks for

complete healing.

The Phase III clinical trial

with PresVIEW includes about

330 patients. Patients are plano

presbyopes between the ages of

50 and 60 without any need for

distance correction; although they

may want to improve their reading

vision, their best corrected distance

visual acuity must be 20/20 or

better. Patients’ eyes are operated on

three weeks apart.

The U.S. trial has reached the

maximum allowed enrollment,

and therefore is no longer enrolling

patients; instead, investigators

around the U.S. are focusing on the

collection of two years of follow-

up data, said Lance Kugler, MD,

Kugler Vision, and University of

Nebraska Medical Center, Omaha,

Neb., USA.

The trial should be complete

by July 2014, according to

ClinicalTrials.gov.

So how’s it working?What is surprising to

investigators is how patients in the

trial are fi nding increased visual

improvement over time, instead

of great visual improvement right

away that might fade with time.

“It’s as if to say, ‘I’m giving you

the gym, you build that muscle up

and work it out,’” Dr. Stonecipher

said, noting that 52 patients have

participated at his practice.

“If you look at our patients

after six months, you see more of

an effect than at three months.

If you look at them at one year,

there’s a better effect than at six

months. The procedure seems to

continue to improve their ability to

see with time,” Dr. Kugler said. “Of

the patients we’ve done, no one has

worsened, and most people have

improved.” Some of Dr. Kugler’s

30 patients no longer need reading

glasses; others still use them for

some tasks, he said.

“Patients have improved

reading vision from the procedure,”

Scleral spacing procedure implant

Scleral spacing procedure implant position behind eyelidsSource (all): Karl G. Stonecipher, MD

Scleral spacing procedure implant procedure steps

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said Brian S. Boxer Wachler,

MD, director, Boxer Wachler Vision

Institute, Beverly Hills. Dr. Boxer

Wachler has been involved with

PresVIEW since its Phase I trials;

in Phase III, he has performed the

procedure in 13 patients/26 eyes.

Although the results have been



positive, the research still needs to

show exactly what makes PresVIEW

effective in target patients, Dr.

Stonecipher said.

The procedure itself will have

some improvements in the near

future, including the previously

mentioned faster surgical speed.

“The company is working on the

device that will make creating

the tunnels a faster process

than it currently is. This will

make it easier for surgeons,”

Dr. Boxer Wachler said.

Some refi nements to

PresVIEW that are undergoing

tests overseas may soon

reach the U.S. and make the

procedure more predictable,

Dr. Kugler said.

There is a risk of anterior

segment ischemia with the

procedure, Dr. Stonecipher

said. However, with the use of

a pupillometer, surgeons can

measure the pupil as needed

and eliminate the chance of

such a problem occurring.

A marketplace fi tIf PresVIEW’s trials have

positive results and the

procedure is approved by the

FDA, investigators envision

the surgery targeting the large

number of plano presbyopes

in the population—and

specifi cally, patients who

want to avoid or cannot

tolerate monovision and who

may need particularly strong

binocular vision, Dr. Kugler

said.

“Right now, we don’t have

a great solution for plano

presbyopes,” Dr. Kugler said.

“You look at scleral spacing

and corneal inlays and other

technology that’s emerging. I

think there will be a role for

all of them, and the demand is

huge.”

Dr. Stonecipher also

sees a role for the various

presbyopic solutions, ranging

from modifi ed monovision to

corneal inlays to lens-based

solutions to a procedure like

PresVIEW.

“I think the market will allow

us to treat different factions of

patients with different options,” he

said.

PresVIEW also fi ts into the

ever-growing presbyopic market

due to both the large population

of plano presbyopes ideal for this

treatment and because patients

who have had previous refractive

surgery are requesting presbyopic

options as they age into their

naturally occurring presbyopia, Dr.

Stonecipher said. EWAP

Editors’ note: Dr. Stonecipher has

fi nancial interests with Refocus Group.

Drs. Boxer Wachler and Kugler have

no fi nancial interests related to this article.

Contact information

Boxer Wachler: 310-860-1900, [email protected]: 400-558-2211, [email protected]: 336-288-8523, [email protected]

n



Strengthening corneas in Singaporeby Matt Young EyeWorld Contributing Writer

Surgeon explains why

and how he performs

crosslinking during many

LASIK procedures

While there are

known risk

factors for

ectasia after

LASIK, analysis of such factors

continues to remain controversial.

Scoring systems can lead to

incorrect predictions of risk factors

that—let’s face it—still aren’t

entirely understood.

Even as surgeons attempt

to screen out bad LASIK

candidates from good ones,

corneal crosslinking is—in some

countries—allowing surgeons to

stabilize many more corneas during

the LASIK procedure.

At least that’s what Jerry Tan,

FRCS, believes.

Dr. Tan, consultant eye

surgeon, Jerry Tan Eye Surgery,

Singapore, has been performing

follow-up for patients who have

undergone corneal crosslinking

during LASIK for the last nine

months.

He is among a select group

of surgeons performing this

procedure outside of the U.S.,

where the procedure has yet to

gain approval from the FDA.

Dr. Tan performs Lasik

Xtra (Avedro, Waltham, Mass.,

USA), which involves corneal

crosslinking, on corneas

potentially at risk for ectasia, on

hyperopic LASIK patients as well as

on very high myopes.

“At present, there is no major

complication we see,” Dr. Tan said.

Dr. Tan explained step by step

how the procedure compares to

a normal LASIK procedure and

his reasons for taking such steps

toward more stable corneas and

ones that do not regress visually.

Risks vs. benefi ts

Despite practicing Lasik Xtra

over the course of the past year, Dr.

Tan readily admits that the body of

scientifi c literature supporting the

procedure could be stronger.

“At the present moment, there

are few papers that have been

written on Lasik Xtra regarding

hyperopia,” Dr. Tan said.

Several peer-review articles

have favorably discussed Lasik

Xtra for high myopia, many just

appearing in the later half of 2012.

Meanwhile, discussion of Lasik

Xtra for hyperopia appears more

prevalently not in peer-reviewed

literature, but at ophthalmic

meetings and in trade articles.

That said, in Dr. Tan’s hands,

the procedure seems to be working

well for hyperopic patients.

“Nobody knows why hyperopic

LASIK seems to be more stable

[with Lasik Xtra],” Dr. Tan said.

“The cornea profi le seems to be

better.”

For its part, Avedro says that

Lasik Xtra preserves “corneal

biomechanical integrity” in

company literature. Essentially,

a ribofl avin formula is applied to

the cornea during LASIK along

with UVA illumination in order

to bring about crosslinking with

the intention of strengthening the

cornea.

Using topography, Dr. Tan

said these hyperopic corneas

post-surgery with Lasik Xtra

look better—i.e., “shapes are

beautiful”—compared to non-Lasik

Xtra procedures. He also feels there

is less regression occurring among

Lasik Xtra cases—a notorious

occurrence among standard

hyperopic LASIK cases.

High myopes also tend to

experience signifi cant regression

after LASIK, but not with Lasik

Xtra, Dr. Tan said.

Performing Lasik XtraSource: Jerry Tan, FRCS

Jerry Tan, FRCS




e

ik

re

g

Views from Asia-Pacifi cColin CHAN, MD, MBBS(Hons), FRANZCOConjoint Associate Professor, SOVS, Faculty of Sci-ence, UNSWClinical Senior Lecturer, Central Clinical School, University of SydneyVision Eye InsititueLevel 4, 270 Victoria Ave., Chatswood, NSW 2067 AustraliaTel. no. +61-9424-9999Fax no. [email protected]

Post-LASIK ectasia is a devastating complication for both the patient and

the refractive surgeon, hence the desperate search for either a screening

or treatment method to reduce the incidence of ectasia. Current screening

methods do not identify all patients with abnormal corneas. For example, the

Randleman Ectasia Risk Factor score1,2, while probably one of the better screening

scales, in our retrospective review would have only identifi ed 56% of ectasia patients

preoperatively as high risk.3

There are too many unknowns about accelerated crosslinking after LASIK or LASIK

Xtra to conclude whether it can reduce the incidence of post-LASIK ectasia. Firstly,

there are no peer-reviewed publications to confi rm that accelerated crosslinking

actually works like conventional crosslinking. Secondly, even if there was evidence

that accelerated crosslinking worked in keratoconus, the parameters used when it is

applied in LASIK Xtra are different again (45 seconds UV exposure versus 3 minutes).

Therefore, no conclusions can be made about its safety and effi cacy with this set

of parameters. Thirdly, crosslinking as a prevention modality is quite a different

proposition from crosslinking as a treatment modality. Ectasia takes a median time

of 4 years to occur and is rare; so suffi cient longitudinal data and signifi cant numbers

are needed to prove LASIK Xtra works.4

My opinion is that there needs to be prospective data on LASIK Xtra before it can be

embraced as preventative treatment for ectasia in high risk corneas. Until then, the

best prevention is in careful case selection. Abnormal corneal topography seems to

be consistently the best predictor of post-LASIK ectasia and if a cornea is potentially

at risk for ectasia, my advice would be simple: don’t operate.

References

1. Randleman JB, Woodward M, Lynn MJ, Stulting RD. Risk assessment for

ectasia after corneal refractive surgery. Ophthalmology. 2008 Jan;115(1):

37-50. Epub 2007 Jul 12.

2. Randleman JB, Trattler WB, Stulting RD.Validation of the Ectasia Risk Score

System for preoperative laser in situ keratomileusis screening. Am J Ophthalmol. 2008 May;145(5):813-8. doi: 10.1016/j.ajo.2007.12.033. Epub

2008 Mar 10.

3. Chan CC, Hodge C, Sutton GExternal analysis of the Randleman Ectasia Risk

Factor Score System: a review of 36 cases of post LASIK ectasia. Clin Experiment Ophthalmol. 2010 May;38(4):335-40.

4. Raj R, Sutton G, Hodge C. “Incidence of Keratectasia after LASIK.” Under

review J Refract Surg.

Editors’ note: Prof. Chan has no fi nancial interests related to his comments.

Lim Li, MBBS, FRCS(Ed), MMed(Ophth), FAMSHead (Clinical Service and Education) and Senior Consultant, Corneal & External Eye Disease ServiceSingapore National Eye Centre11 Third Hospital Ave., Singapore 168751Tel. no. [email protected]

Corneal collagen crosslinking treatment has been shown to be effective in stabilizing corneal ectatic conditions such as keratoconus and post-LASIK keratectasia.1-3 The creation of a LASIK fl ap reduces the biomechanical strength

of the cornea. The structural integrity of the cornea can be weakened especially in high myopia treatment. In recent years, post-LASIK iatrogenic keratectasia has become a signifi cant problem for many refractive surgeons and LASIK patients. Over time, with the increasing number of eyes treated with LASIK, more and more corneas are likely to suffer mechanical fatigue resulting in ectasia. The incidence of post-refractive corneal ectasia is unknown, but it has been estimated by some to be as high as 1 in 1000 cases after LASIK surgery.

Traditionally, corneal collagen crosslinking is generally performed by removing the corneal epithelium and then pretreating the cornea for 30 minutes with 0.1% Ribofl avin Ophthalmic Solution to saturate the corneal tissue with the ribofl avin photosensitizer. The cornea is then irradiated with UVA (365 nm) at 3 mW/cm2 for 30 minutes. The whole procedure takes an hour to perform.

By using higher UVA irradiance, the Avedro corneal crosslinking system signifi cantly reduces crosslinking time from one hour to a few minutes. There are currently two indications for this system: KXL procedure for the treatment of keratoconus and LASIK ectasia and the Lasik Xtra procedure for prophylactically crosslinking during LASIK surgery. Both procedures have received the CE mark approval for use in Europe and are currently undergoing FDA trials in the USA. However, prophylactic crosslinking in LASIK is a new emerging technique with few published results todate. Celik4 reported in a case series of 8 eyes (fellow eye as control) that the LASIK – CXL group had equal or better visual outcome than the LASIK only group. Further long term follow-up and clinical evaluations are required.

References

1. Wollensak G, Spoerl E, Seiler T. Ribofl avin/Ultraviolet-A-induced collagen cross-linking for the treatment of keratoconus. Am J Ophthalmol. 2003; 135:620-627.

2. Caporossi A, Mazzotta C, Baiocchi S, Caporossi T. Long term results of ribofl avin ultraviolet a corneal collagen cross-linking for keratoconus in Italy: the Siena eye cross study. Am J Ophthalmol. 2010 Apr;149(4):585-93.

3. Vinciguerra P, Albe E, Trazza S, Seiler T, Epstein D. Intraoperative and postoperative effects of corneal collagen cross-linking on progressive keratoconus. Arch Ophthalmol. 209 Oct;127(10):1258-65.

4. Celik HU, Alagöz N, Yildirim Y, et al. Accelerated corneal crosslinking concurrent with laser in situ keratomileusis. J Cataract Refract Surg. 2012 Aug;38(8):1424-31.

Editors’ note: Dr. Lim has no fi nancial interests related to her comments.

43


42 EWAP rEfrActivE March 2013

ORGANISED BY:

AND

```

CIC04: Optimizing Outcomes in Toric IOLsTetsuro OSHIKA, GUO Haike, Ronald YEOH

MC06: Flawless Femto LASIK Flaps

MC01: Mastering Femto Phaco Cataract Surgery

MC02: Glued IOL

MC03: From FLEx to SMILE

WL01: Basic Phaco hands-on Wetlab with KITARO Wetlab System

Core Instructional Courses & Masterclasses

CIC01: Phaco Fundamentals

CIC02: Retinal Updates for Anterior Segment Surgeons

CIC03: Ocular Trauma

1100 - 1300 hrs

1330 - 1500 hrs

1530 - 1700 hrs

0830 - 1000 hrs

- All Core Instructional Courses and MasterClasses will be held at SUNTEC Singapore (included in meeting registration) - All Hands-on Wetlab sessions will be held at the Singapore National Eye Centre (separate charge applies)

CIC05: Tips & Tricks for Successful Pterygium Surgery

CIC06: What the Refractive Surgeon Needs to Know about Glaucoma

1045 - 1215 hrsMC04: Finer Points in IOL Fixation

WL02: Basic Phaco with KITARO Wetlab System


Hands-on Wetlabs

Log on to www.2013apacrs.org for registration

1345 - 1545 hrs

1600 - 1800 hrs

Learn expert techniques from the best practitioners with our new series of Core Instructional Courses, MasterClasses and Hands-on Wetlabs!

11 July 2013 (Thursday)


Ronald YEOH, CHEE Soon Phaik, Gerard SUTTON, Michael KNORZ, Zoltan NAGY

Amar AGARWAL, Athiya AGARWAL, Roger STEINERT, Keiki MEHTA

Johan HUTAURUK, CHEE Soon Phaik, Hadi PRAKOSO, TI Seng Ei

ANG Chong Lye, Manish NAGPAL, LEE Shu Yen, ONG Sze Guan, Ian YEO, Doric WONG, Edmund WONG

Gangadhara SUNDAR, Hunter YUEN, Paul CHEW, S. NATARAJAN

Donald TAN, Jodhbir S. MEHTA, Kimiya SHIMIZU

Cordelia CHAN, Gerard SUTTON, Donald TAN

CHEE Soon Phaik, Ronald YEOH, Roger STEINERT

Shamira PERERA, John CHANG, Prin ROJANAPONGPUN, ZHOU Qi

MC05: Advanced BiometryFAM Han Bor, Wolfgang HAIGIS, John SHAMMAS

CHAN Wing Kwong, Cordelia CHAN, Choun-Ki JOO, WANG Zheng

TI Seng Ei, Johan HUTAURUK, Akura JUNSUKE, YC Lee

12 July 2013 (Friday)

WL04: DSAEK Hands-on Wetlab 1600 - 1800 hrs

Hands-on Wetlab

Donald TAN, LIM Li, Jodhbir S. MEHTA(Limit to 8 participants only)

Hosted by the Asia Cornea Society and the Cornea Society



ORGANISED BY:

AND

```




MC02: Glued IOL







1100 - 1300 hrs

1330 - 1500 hrs

1530 - 1700 hrs

0830 - 1000 hrs







Hands-on Wetlabs


1345 - 1545 hrs

1600 - 1800 hrs

















WL04: DSAEK Hands-on Wetlab1600 - 1800 hrs

Hands-on Wetlab





In fact, while standard LASIK

patients experience a “wow”

factor almost immediately post-

op, that effect tends to diminish

with regression over the course

of weeks and months in high

myopes. With Lasik Xtra, it’s just

the opposite, Dr. Tan said. A small

amount of myopia tends to remain

immediately post-op, and vision

continues to improve to plano until

about the three-month follow-up

period, he said.

“The patients tell me they see

better and better,” Dr. Tan said. “So

I am getting late-onset ‘wows.’”

Dr. Tan much prefers late-

onset “wows” to regression, and so

do his patients, he said. Patients

potentially at risk for ectasia (i.e.,

young patients, those with thinner

corneas, etc.) also appreciate

the added potential safety that

crosslinking allows.

in my hands

Normally, corneal ectasia

develops anywhere from two to

four years after LASIK and even as

late as 10 years post-op, Dr. Tan

said.

“This is something very

difficult to predict in normal eyes,”

Dr. Tan said. “So I do [Lasik Xtra]

on all high myopes, and all patients

who have a residual corneal

thickness of 250-300 microns in

the stromal bed underneath the

flap. I tell the patient, ‘I think you

need Lasik Xtra just in case I make

the cornea too weak.’ Most of them

say, ‘If it’s no risk to me, I just get a

bit of insurance.’”

As noted earlier, Dr. Tan also

performs Lasik Xtra on hyperopes.

Normally, Dr. Tan starts out

the LASIK procedure with IntraLase

(Abbott Medical Optics, Santa Ana,

Calif., USA). He makes a 100- to

Strengthening - from page 40

ORGANISED BY:

AND

```




MC02: Glued IOL







1100 - 1300 hrs

1330 - 1500 hrs

1530 - 1700 hrs

0830 - 1000 hrs







Hands-on Wetlabs


1345 - 1545 hrs

1600 - 1800 hrs

















WL04: DSAEK Hands-on Wetlab1600 - 1800 hrs

Hands-on Wetlab





33-42_EW REAFTIVE.indd 42 25/03/2013 17:13


In fact, while standard LASIK

patients experience a “wow”

factor almost immediately post-

op, that effect tends to diminish

with regression over the course

of weeks and months in high

myopes. With Lasik Xtra, it’s just

the opposite, Dr. Tan said. A small

amount of myopia tends to remain

immediately post-op, and vision

continues to improve to plano until

about the three-month follow-up

period, he said.

“The patients tell me they see

better and better,” Dr. Tan said. “So

I am getting late-onset ‘wows.’”

Dr. Tan much prefers late-

onset “wows” to regression, and so

do his patients, he said. Patients

potentially at risk for ectasia (i.e.,

young patients, those with thinner

corneas, etc.) also appreciate

the added potential safety that

crosslinking allows.

In my hands

Normally, corneal ectasia

develops anywhere from two to

four years after LASIK and even as

late as 10 years post-op, Dr. Tan

said.

“This is something very

diffi cult to predict in normal eyes,”

Dr. Tan said. “So I do [Lasik Xtra]

on all high myopes, and all patients

who have a residual corneal

thickness of 250-300 microns in

the stromal bed underneath the

fl ap. I tell the patient, ‘I think you

need Lasik Xtra just in case I make

the cornea too weak.’ Most of them

say, ‘If it’s no risk to me, I just get a

bit of insurance.’”

As noted earlier, Dr. Tan also

performs Lasik Xtra on hyperopes.

Normally, Dr. Tan starts out

the LASIK procedure with IntraLase

(Abbott Medical Optics, Santa Ana,

Calif., USA). He makes a 100- to

110-micron fl ap.

Dr. Tan applies the ribofl avin

(without dextran) for 45 seconds to

the stroma, rinsing any excess from

the fl ap. Then he puts the fl ap back.

Dr. Tan applies UV light (30

mW/cm2) to the cornea for 45

seconds. Afterward, he waits an

additional minute. That’s it. These

are the only procedural differences

compared to standard LASIK.

For Dr. Tan, this means no

additional time to the LASIK

procedure required.

Normally when Dr. Tan doesn’t

perform Lasik Xtra, after putting

the fl ap back, he waits three

minutes and then fi nishes the

procedure.

“I like to wait three minutes

for my fl ap to really stick on well

so there are no fl ap shifts [during

standard LASIK],” Dr. Tan said. “I

used to wait one minute but then

would occasionally get a few fl ap

shifts. Then I waited two minutes

and rarely would get fl ap shifts.

When I wait three minutes I get

no fl ap shifts. For the last few

thousand cases I have never had a

fl ap shift. So I wait three minutes.

It seems to be a nice magic fi gure

for me.”

Now instead of waiting

three minutes, he performs the

crosslinking component during

this time. With the ribofl avin

component, UVA illumination

component, and added machines

moving about during crosslinking,

the time involved is identical to Dr.

Tan’s standard LASIK procedure.

“It doesn’t increase my time

for surgery at all, at least for my

technique,” Dr. Tan said.

Drawbacks vs. drawbacks

Initially, Dr. Tan said he was

standard LASIK with the MEL 80

excimer laser (Carl Zeiss Meditec)

with no eyes losing more than one

line CDVA. Mean post-op mesopic

contrast sensitivity was either the

same or slightly better than pre-op

at 3, 6, 12, and 18 cpd for all three

populations, using the CSV-1000.

In summary, Presbyond Laser

Blended Vision is a solution for

presbyopia that meets all the

goals of good binocular vision

at all distances, no compromise

in safety, contrast sensitivity,

or night vision, and retention

of functional stereo acuity. The

procedure is immediately reversible

by wearing spectacles, or a simple

retreatment can be done using a

standard excimer laser ablation

with the advantage of keeping the

depth of fi eld. All this is achieved

while simultaneously correcting a

wide range of refractive errors and

astigmatism levels.

he key to this approach

was to base it on the natural

mechanisms of spherical aberration

processing and binocular fusion,

unlike multifocal approaches that

require the patient to adjust to the

unnatural situation of having to

differentiate between two images in

the same eye. EWAP

Editors’ note: Dr. Reinstein practices

at the London Vision Clinic, London,

England, UK, and is affi liated with

the Department of Ophthalmology,

Columbia University Medical College,

New York, NY, USA, and the Centre

Hospitalier National d’Ophtalmologie,

Paris, France. He has fi nancial

interests with Carl Zeiss Meditec and

ArcScan Inc. (Morrison, Colo., USA).

Contact information

Reinstein: +44 020 7224 1005,

[email protected]

Presbyond - from page 37Strengthening - from page 40

using a ribofl avin formula that

included dextran during the Lasik

Xtra procedure.

“When you leave dextran

underneath the fl ap, it causes a

little bit of DLK,” Dr. Tan said.

“With the new formulation of

ribofl avin without dextran—with

just normal saline—there is no

DLK.”

The DLK experienced

previously was mild, grade 1 DLK,

he said.

While the jury is still out

on the long-term effects of

crosslinking, Dr. Tan is convinced

that it is safer than performing

PRK with mitomycin-C, another

refractive surgery option for higher

myopia that reduces the risk of

ectasia.

“If you have a choice between

crosslinking and mitomycin-C,

mitomycin-C is more dangerous,”

he said.

Meanwhile, Lasik Xtra is a

better option than the Visian ICL

(STAAR Surgical, Monrovia, Calif.,

USA) for many cases in Singapore,

he said.

Dr. Tan described the typical

Singaporean myope as having

“long eyeballs and anterior

chambers that are too shallow for

the Visian ICL.

If I try to [implant a Visian ICL]

in Singapore, the anterior chamber

is going to be too small.”

Referring to Lasik Xtra, Dr. Tan

said, “If there is no downside, why

not do it?” EWAP

Editors’ note: Dr. Tan has no fi nancial

interests related to this article.

Contact information

Tan: +65 6738 8122,

[email protected]

,


44 EWAP CORNEA March 2013

Cornea surgeons compare thin DSAEK and DMEK as options for endothelial keratoplasty procedures by Ellen Stodola EyeWorld Staff Writer

DMEK gaining ground on

DSEK

When it comes to

corneal endothelial

disorders, endothelial

keratoplasty

has become popular with

ophthalmologists worldwide,

and many choose between

Descemet’s stripping endothelial

keratoplasty (DSEK) and Descemet’s

membrane endothelial keratoplasty

(DMEK). DSEK seems to be the

current preferred method, with

developments in DMEK causing the

technique to gain ground.

DSEK involves a transplant

of the back layers of a donor

cornea into a patient’s eye. This

technique offers a certain ease

because it has been the procedure

of choice for many years. DSAEK

is the automated version of this

procedure, which uses a machine to

cut tissue.

DMEK, on the other hand, uses

extremely thin donor tissue, with

a better chance of restoring good

vision to the patient. However,

surgeons using this technique often

experience obstacles with handling

the donor tissue because of how

fragile the grafts can be.

Recently, thin DSAEK has

offered an alternative to the other

two techniques, utilizing the ease

of DSAEK with thinner grafts.

Massimo Busin, MD, Villa

Igea Hospital, Forli, Italy, is one of

the surgeons who has been seeing

the benefi ts thin DSAEK can offer,

and he compared the advantages

and disadvantages doctors see using

both DSAEK and DMEK. Similarly,

Andrea Ang, MD, Royal Perth

Hospital, Perth, Western Australia,

prefers using the thin DSAEK

technique, but she also pointed

out the advantages of both DSAEK

and DMEK. Meanwhile, Francis

Price, MD, Price Vision Group,

Indianapolis, favors DMEK and

stressed some of its key advantages.

The outcomes of each tech-nique

“Both techniques have

developed because the results of

the old conventional penetrating

keratoplasty were not as satisfactory

as one would like them to be,” Dr.

Busin said. Advancements were

initially made by DSAEK, he said.

However, he said that some

physicians felt that there was only

a limited number of eyes gaining

20/20 vision after surgery. This

prompted the development of

DMEK, which was an attempt to

increase the number of eyes that

would be able to obtain 20/20

vision after surgery.

Dr. Ang agreed with the

advantages of DSAEK over

penetrating keratoplasty and also

with the argument that only a

limited number of patients achieve

20/20 vision.

“Recent DMEK studies have

shown faster visual rehabilitation

and better visual outcomes than

the earlier DSAEK studies,” Dr.

Ang said. “However, recent studies

have shown that the thickness of

donor tissue used in DSAEK does

infl uence visual outcome, with

newer thin DSAEK techniques

demonstrating improved visual

outcomes approaching the visual

OCT image of a post-op thin DSAEK; central donor thickness is 100 micronsSource: Edward J. Holland, MD

OCT image of a post-op thin DSAEK; central donor thickness is 100 micronsSource: David Vroman, MD

outcomes seen with DMEK and

with less complications.”

One of the reasons many

surgeons tend to prefer DSAEK

to DMEK is simply the ease

with which the surgery can be

performed.

“It’s much easier to perform a

DSAEK, even with a thin graft, than

it is to perform a DMEK,” he said.

To back up his point, Dr. Busin

said that in the U.S. last year,

there were over 21,000 DSAEK

procedures, compared to around

343 DMEK procedures.

Dr. Ang said new insertion

devices like the EndoSerter (Ocular

Systems, Winston-Salem, NC, USA),

the Busin Glide (Moria, Antony,

France), and the Tan EndoGlide

(Angiotech, Vancouver, BC) help to

handle the tissue for insertion. “At

the present, thin DSAEK appears an

attractive alternative while DMEK

techniques continue to improve,”

she said.

Complications arising

Despite DSAEK standing out

as the easier technique, there are

other factors to consider. DSAEK is

often preferred to DMEK because

primary failure is more common

with DMEK, Dr. Busin said. He

said DMEK poses the threat of

a signifi cant detachment rate.


44-48 EWAP Corena.indd 4444-48 EWAP Corena.indd 44 21/03/2013 17:2821/03/2013 17:28

45EWAP CORNEAMarch 2013

D

D

o

n

Views from Asia-Pacifi cAlvin Lerrmann YOUNG, MDChief of Service, Department of Ophthalmology & Visual Sciences, The Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong SARTel. no. +852-26322878Fax no. [email protected]

There has been a major paradigm shift in the fi eld of corneal transplantation since the advent of modern endothelial keratoplasty. The popularity of the technique has been widespread. One of the main reasons for this immense positive response about this surgery is the relative ease of performing the whole procedure. In the earlier days, DLEK (deep lamellar endothelial keratoplasty) surgery was technically more demanding and diffi cult hence subsequently replaced by DSEK. Most corneal surgeons are now using DSEK or DSAEK depending upon the availability of an automated micokeratome or precut tissue in their set up. More recently, the focus of discussion has shifted to the use of thin donor lenticules, consequently bringing ultra-thin DSAEK and DMEK to the forefront. However, there are certain pertinent issues that need to be considered before these relatively new surgeries can be adopted. Obtaining a thin-cut donor lenticule or only the Descemet’s membrane (in DMEK) can be a diffi cult proposition resulting in inadvertent wastage of human tissue, which certainly is not affordable in countries where there is an obvious dearth of donor corneas. In addition, using two microkeratome heads for ultra-thin DSAEK lenticules would impose extra fi nancial burden in less affl uent economies and especially when these heads are disposable. Furthermore, Asian eyes are commonly found to have shallow anterior chambers, limiting the freedom of movement inside the eye when the surgeon in trying to “center” or orientate a very thin donor lenticule. The situation becomes worse if another intervention, such as refl oating the graft, is required.

At the moment, there is still a relative scarcity of reports on excellent visual outcomes after thin lenticule DSAEK or DMEK. In the absence of any long-term comparative clinical trials, one needs to weigh the benefi ts and risks that are local in terms of graft availability, preparation, wastage rate, patient factors and surgeons’ expertise in deciding whether or not to adopt thin lenticule DSAEK, DMEK, or to ‘settle with’ a fairly confi dently attainable visual acuity of 20/30 with conventional DSEK/DSAEK. As mentioned earlier, the ease of performing a conventional DSEK/DSAEK is one of the highlights of this surgery. Further research and refi nement towards innovation of better technology and techniques aiming toward the better and safer preparation of donor material (perhaps best served by an eye bank), surgical handling of donor and its insertion are warranted.

Editors’ note: Dr. Young acknowledges the kind assistance of Dr. Vishal Jhanji in writing his comments. Dr. Young has no fi nancial interests related to his comments.

Tae-Im KIM, MDAssociate Professor, Yonsei University, Dept. of Ophthalmology, 50 Yonsei-ro, Seodaemun-gu, Seoul, KoreaTel. no. +82-2-2228-3570Fax no. [email protected]

Over the years, keratoplasty has been developed and has recently diversifi ed from penetrating keratoplasty (PK) to refi ned lamellar keratoplasty. Anterior stromal corneal abnormality was corrected by lamellar keratoplasty or deep lamellar keratoplasty using various techniques. The posterior part of the cornea abnormality, mainly related with endothelial dysfunction, was treated by selective replacement of diseased recipient endothelium via Descemet’s stripping endothelial keratoplasty (DSEK) or Descemet’s membrane endothelial keratoplasty (DMEK).

In Descemet’s stripping automated endothelial keratoplasty (DSAEK), the outer layers of the cornea are skimmed off using a mechanical microkeratome, leaving a very thin layer of stromal fi bers supporting the inner Descemet’s membrane and the endothelial cells. The bottom 20% of divided cornea is used for DSAEK and the top 80% can be used as donor tissue for anterior lamellar transplants. Automated cutting improves the donor preparation procedure with smooth cut surfaces and predictable thickness. The quality of the visual recovery after DSAEK is generally better than that achieved by a penetrating graft. The stability of the refraction and rapid visual rehabilitation are major advantages of all endothelial keratoplasty techniques. However, because of the remaining stromal tissue and the interface, DSAEK still shows suboptimal visual acuity and relatively slow visual rehabilitation. Also, expensive equipment and a drop in donor endothelial cell density in the early postoperative period remain drawbacks. In an attempt to overcome these limitations, pioneering corneal surgeons have invented the donor preparation surgical procedure to minimize the remaining stromal tissue. The donor Descemet’s membrane is scored and trephined from the endothelial side without any donor corneal stroma. Also, there is no need for an artifi cial anterior chamber or a microkeratome in the donor tissue preparation. This DMEK procedure can accelerate the recovery and increase the chance of obtaining 20/20 vision postoperatively. Moreover, the rate of rejection with DSAEK can be successfully reduced by minimizing antigen exposure. However, DMEK is a more challenging procedure than established DSAEK surgery. DMEK has the potential of infl icting damage to the donor endothelium and Descemet’s membrane during the surgical preparation and introduction into the anterior chamber.

The pros and cons of each advanced posterior lamellar replacement procedure have been proven. However, apart from the results of each procedure, an important factor in selecting particular surgical technique is the experience of the operating surgeon. Even though the surgical outcome of DMEK is superior in many aspects, the surgeon with lack of surgical experience and limited skills may elect not to choose DMEK. Too aggressive trial of a diffi cult procedure may induce signifi cant added cost to this surgery.

In the near future, better surgical techniques and instruments will be introduced to facilitate DMEK procedure without jeopardizing the surgical outcome. Until then, DSAEK will account for a great part of posterior lamellar procedures.

Editors’ note: Dr. Kim has no fi nancial interests related to her comments.

46



However, he also said DMEK

typically has a lower rejection rate.

Dr. Ang said “safety in

donor preparation and easier

manipulation of the tissue in the

anterior chamber” is a factor that

continues to make the DSAEK

technique more popular. “The

challenge for thin DSAEK is for

the eye banks to come up with

techniques to provide reproducible

and accurate thin tissue,” she said.

Tissue loss and possibility

of endothelial cell loss because

of diffi culties manipulating the

delicate tissue were two possible

risks with DMEK that Dr. Ang

cited. “Solutions to these problems

need to be found in order to make

DMEK the procedure of choice for

endothelial replacement,” she said.

Technique preferences

Dr. Busin said he is currently

seeing a trend toward thin

DSAEK, his preferred method.

This allows for thinner grafts and

thinner incisions with the DSAEK

procedure. However, he said that

some people may not trust this

method yet, which could be why

some are leaning toward DMEK. He

said in the future he expects to see

people favoring thin DSAEK.

“The ease of surgery and the

outcome, which is more or less

the same, would convince them

to move from DMEK back to thin

DSAEK grafts,” Dr. Busin said.

Likewise, Dr. Ang also said thin

DSAEK is presently her procedure

of choice. “This technique results

in excellent visual outcomes, is

technically less demanding than

DMEK, and has fewer complications

than DMEK at present,” she said.

Dr. Price said he prefers the

DMEK technique, although he

still sometimes uses DSAEK. “If

it’s a non-complicated case, we

recommend DMEK,” he said. After

nearly fi ve years using DMEK,

there are a number of reasons

he favors it. He said better vision

results are evident with DMEK.

Another reason is rejection rates are

signifi cantly lower with DMEK. He

said in a cumulative look at DMEK

for a two-year period, the rejection

rate was less than 1%, compared to

about 12% for DSAEK.

He said thin DSAEK does offer

some similarities to DMEK. “I think

the thinner it gets, the closer you’re

going to get to DMEK,” he said. But

the question, he said, is how close

you can get and how reliable the

thin DSAEK would be. Dr. Price

said he stopped using thin DSAEK

because of signifi cant tissue loss

in donor preparation. Currently

DMEK donor loss rates are less

than 1%; it will be interesting

to see if donor loss rates will be

that low if all donor preparations

for DSAEK are for thin cuts, as

there is always some irregularity

and unpredictability with

microkeratome cuts.

Endothelial replacement future

Endothelial keratoplasty has

evolved over the years, Dr. Ang said.

“The next phase will be cultured

donor endothelial cell seeding of

diseased corneas,” she said. “The

ability to culture and expand donor

endothelial cells will increase

the donor supply, especially in

countries with limited supply.

These cells could be transplanted

either as an injection-based therapy

or on a carrier.” EWAP

Editors’ note: Dr. Busin has fi nancial interests with Moria. Drs. Ang and Price have no fi nancial interests related to this article.

Contact informationAng: [email protected]: [email protected]: [email protected]

L

tr

p

Tm

gr

Th

St

tr

en

co

at

da

in

da

“R

ar

Cornea - from page 44

LASIKSurgery

• Thin, 100-micron, planar flaps

• Accuracy and predictability equivalent to Femto-SBK

• Smoother stromal bed

• No femto-complications

• … At a fraction of the cost

Think Thin

SBK without femto-furrow

James Lewis, MD(Elkins Park, PA, USA)


47EWAP CORNEAMarch 2013

Expanding corneal tissue availability

Largest cornea clinical

trial today compares

preservation time

The largest clinical trial

in the fi eld of cornea

diseases and surgery at

the moment eventually

may increase the number of corneal

grafts available for transplantation.

The Cornea Preservation Time

Study (CPTS) will track the

transplantation success rate in

endothelial keratoplasty with donor

cornea preserved in storage medium

at 4 degrees Celsius for up to seven

days versus donor cornea preserved

in storage media for eight to 14

days.

“Right now, surgeons and eye banks

are reluctant to go beyond seven

by Vanessa Caceres EyeWorld Contributing Writer

days,” said study chair Jonathan

H. Lass, MD, director, University

Hospitals Eye Institute, and Charles

I. Thomas Professor and chair,

Department of Ophthalmology

and Visual Sciences, Case Western

Reserve University School of

Medicine, Cleveland, Ohio, USA.

However, the U.S. FDA has

approved the storage of cornea

tissue in approved media at 4

degrees Celsius for up to 14 days,

leading investigators to believe that

there may be a waste of good tissue

occurring.

“The eye banks many times are

hitting one week to place the

tissue and must then explore other

options with surgeons out of the

country so that the tissue gets

utilized,” Dr. Lass said.

Study details

To compare the results of cornea

donor tissue at one week versus

eight to 14 days, study investigators

at 40 participating clinical sites

nationwide are enrolling up to

1,330 patients. As of the beginning

of January, the study had enrolled

556 eyes, said Dr. Lass. Patients are

randomized into one of two groups.

Eyes in the fi rst group receive tissue

that has been preserved for up to

seven days. Eyes in the second

group receive tissue that has been

preserved for eight to 14 days.

Neither the surgeon nor the patient

know to which group the eye was

randomized.

Investigators will follow patients

for up to three years to see if the

two groups have any difference

in transplantation success or

differences in the number of

transplanted endothelial cells.

Investigators believe they will

fi nd no signifi cant difference in

outcomes comparing the two

groups.

The trial began in April 2012.

Because of the three-year follow-up,

early 2017 is the soonest point at

which results will be available, Dr.

Lass said.

The CPTS is supported with a $12.3

million grant from the National

Eye Institute, Dr. Lass said. The

Jaeb Center for Health Research in

Tampa, Fla., USA, is collecting the

study data.

Research benefi ts

Although the U.S. does not

Clear Equivocal Cloudy

CPTS corneal recipient stroma clarity grading scale for endothelial keratoplastySource: George Rosenwasser, MD




currently have a shortage of donor

corneas, there could be numerous

benefi ts if the study shows that

the longer storage time is just as

effective as the shorter storage time.

First, there’s an expected increase

in demand for corneal tissue as

the U.S. population ages, Dr. Lass

said. “If we can show preservation

time doesn’t make a difference, we

could double the supply that people

would be willing to use,” he said.

In addition, the donor pool is

at a greater risk from emerging

infections like the West Nile virus,

and the eye banks need more

time to screen donors because

of the concerns about infections

surrounding drug addiction,

including hepatitis B.

This kind of research will provide

actual evidence regarding best

practices for corneal preservation

timing and usage, Dr. Lass said.

“We want to have an evidence-

based approach to deal with

perceptions surrounding the

donor cornea and provide greater

fl exibility for eye banks in placing

tissue,” he explained.

George Rosenwasser, MD,

Central Pennsylvania Eye Institute,

Hershey, Pa., USA, whose practice

is participating in the trial, is eager

to see if the results provide proof

that the longer preservation time

is just as clinically acceptable as

the shorter preservation time. He

routinely has used tissue that has

been preserved for 10 to 11 days

and has found no difference in

outcomes or quality compared with

tissue preserved for a shorter time.

Currently, the U.S. has the most

organized eye banking process

in the world and often shares its

excess supply around the world,

said Kevin Ross, president and

CEO, Midwest Eye-Banks, Ann

Arbor, Mich., USA. There were

about 46,000 corneal transplants

performed in the U.S. in 2011,

according to Eye Bank Association

of America statistics, Mr. Ross said.

However, there were 67,590 donor

tissues available in 2011. The tissue

that are not used—for 2011, that

was a little over 30%—are typically

shipped overseas.

Although the U.S. does not have a

shortage of donor tissue, there’s a

“tremendous shortage” elsewhere,

Mr. Ross said. “There are about

100,000 to 150,000 corneal grafts

in the world each year,” Mr. Ross

said. “The number needed is closer

to a million.”

The CPTS results may help close

that gap. “We could provide a major

benefi t for the restoration of sight

in many places, fi rst and foremost

in the U.S. This could also give us

the opportunity to support corneal

surgery programs around the

world,” Mr. Ross said, noting that

many U.S. eye banks are involved

with supporting cornea surgery

programs globally.

That said, if the U.S. has an

increasing need for donor tissue,

the study results could help meet

the demand in the U.S., Dr. Lass

said.

The results will affect eye banks’

policies and procedures that guide

for how long donor tissue can be

used, Mr. Ross added. They also will

likely affect tissue criteria selection

worldwide, he said.

The study is actively recruiting

patients between the ages of 30 and

<91. Patients at participating centers

with either Fuchs’ dystrophy or

Expanding - from page 47

pseudophakic bullous keratopathy

undergoing Descemet’s stripping

endothelial keratoplasty (DSEK)

must be available for follow-ups at

one day, one week, one month, and

six months, and one, two, and three

years. The study’s website is cpts.

jaeb.org. EWAP

Editors’ note: The physicians have no fi nancial interests related to this article.

Contact informationLass: 216-844-8590, [email protected]

Rosenwasser: 717-533-5200, [email protected]

Ross: 734-780-218, [email protected]


49EWAP GLAUCOMA March 2013

Studies highlight the relationship between diet and glaucoma

Can what we eat increase

our risk of getting

glaucoma? A trio of

studies presented at this

year’s American Glaucoma Society

meeting suggested that the answer

might be yes.

The pathophysiology of

glaucoma is poorly understood.

The primary risk factor, IOP, has

a complex relationship with the

disease, being frequently elevated

but neither necessary nor suffi cient

to explain the majority of cases of

glaucoma. Based on the high risk

of glaucoma among fi rst-degree

relatives, a genetic basis is strongly

suspected. Major genetic studies,

however, have failed to fi nd a gene

or genes that account for more than

a small percentage of primary open-

angle glaucoma cases. This has

led many to speculate that gene-

environment interactions may be at

play. This is a two-hit mechanism

of sorts: having the gene isn’t

enough—one must also have a

specifi c environmental exposure.

To date, the nature of such an

environmental factor has been

unknown. New data suggests that it

might be diet-related.

Nutrients and oxidative stress“Oxidative stress may be an

important component of the

pathophysiology of glaucoma,”

said Sophia Wang, BA, medical

student, University of California-

San Francisco, Calif., USA. Calcium

and iron, she said, are two dietary

elements that play a role in the

formation of highly reactive oxygen

species that can damage tissues. She

proposed that high dietary intake

of these nutrients, coupled with

impaired regulation of homeostatic

regulatory processes due to aging,

could lead to damage to the

trabecular meshwork, loss of retinal

ganglion cells, and the clinical

manifestations of glaucoma.

To explore this hypothesis, Ms.

Wang conducted a cross-sectional

epidemiologic study utilizing the

National Health and Nutrition

Examination Surveys

(NHANES) database, which

contains detailed information on

the dietary intake of large numbers

of Americans as well as their

glaucoma status by self-report.

“We analyzed data from 3,833

adult Americans, of whom 248

self-reported having glaucoma,” she

said.

Ms. Wang found that people

consuming the highest levels of

calcium—more than 800 mg/

day—were 2.4 times more likely to

self-report having glaucoma than

those consuming the lowest levels

of calcium. Also, people consuming

the highest levels of iron—more

than 18 mg/day—were 3.8 times

more likely to self-report glaucoma

than those consuming the lowest

levels of iron.

People consuming the highest

levels of both calcium and iron, she

said, had a 7.2 fold higher odds of

glaucoma.

Louis Pasquale, MD,

Massachusetts Eye and Ear

Infi rmary, Boston, Mass., USA,

said, “This is the fi rst human data

in support of an oxidative stress

mechanism in glaucoma.”

Can diet infl uence the risk of glaucoma?by Tony Realini, MD

CaffeineDr. Pasquale has studied the

incidence of pseudoexfoliation

glaucoma between 1980 and 2008

and its relationship to caffeine

intake utilizing the Nurses Health

Study database. This database

included data on nutritional

intake as well as fi ndings on eye

examinations. He identifi ed 300

new cases of pseudoexfoliation

glaucoma among 1.6 million

person-years of follow-up.

“We observed a positive

association between overall caffeine

intake and pseudoexfoliation

that was not quite statistically

signifi cant,” he said. But for those

who get their caffeine specifi cally

from coffee—drinking at least

three cups a day—the risk of

pseudoexfoliation was 63% higher

than for non-coffee drinkers.

Interestingly, the effect of

caffeine intake was modifi ed by

family history. “Among those

consuming the highest levels of

caffeine, people who also had a

family history of glaucoma had a

2.9-fold higher risk of glaucoma,

compared to only a 1.2-fold

increase for those without a family

history,” he said.

This supports the concept of

a gene-environment interaction

for caffeine and pseudoexfoliation

glaucoma, he said.

Caffeine and IOPTo evaluate how caffeine might

affect glaucoma, Aliya Jiwani, in

collaboration with Dr. Pasquale and

others, conducted a randomized

trial to explore caffeine’s effect on

IOP and ocular perfusion pressure

(OPP) in healthy subjects, glaucoma

suspects, and patients with both

low-tension and high-tension

glaucoma.

In their crossover study,

patients drank an 8-oz. cup of

caffeinated coffee at one visit

and an 8-oz. cup of decaffeinated

coffee at a second visit, in a

randomized order. IOP and OPP

were determined before and 60 and

90 minutes after each beverage.

Compared to decaffeinated

coffee, caffeinated coffee raised IOP

by 1 mmHg at both time points,

and raised OPP by 1.6 mmHg and

1.3 mmHg at 60 and 90 minutes,

respectively. Although the changes

were statistically signifi cant, she

said, the effect size was quite small.

“Consuming a single 8-oz. cup

of caffeinated coffee likely does not

clinically impact IOP or OPP,” she

concluded.

Dr. Pasquale agreed. “This is the

beginning of a conversation about

the role of environmental factors

associated with the development

of glaucoma,” he said. “It is still

too early to begin recommending

lifestyle changes for our glaucoma

patients.”

But he sees the potential for

signifi cant progress in this research

area in the future. “We may be

able to prevent pseudoexfoliation

glaucoma in the decades to come,”

Dr. Pasquale said. EWAP

Editors’ note: Ms. Wang has no

fi nancial interests related to this

article.

Contact information

Jiwani: [email protected]

Pasquale:

[email protected]

Wang: [email protected]

49-50_ EWAP Glaucoma.indd 4949-50_ EWAP Glaucoma.indd 49 21/03/2013 17:2921/03/2013 17:29

50 EWAP GLAUCOMA March 2013

New technology could improve eye drop deliveryby Ellen Stodola EyeWorld Staff Writer

New delivery system

seeks to address the

need for more effective

administration of

medication

The eye dropper is a

technology that has

changed relatively little

over time, but many

doctors have recently seen a need

to adapt the device to make it more

effective for patients attempting to

use it to administer medications.

Sean Ianchulev, MD, clinical

associate professor, University

of California, San Francisco,

Calif., USA, recently presented on

results of a study for the new eye

droplet device being developed by

Corinthian Ophthalmic (Raleigh,

NC, USA). The new delivery system

would work to remedy some of the

obstacles to patients trying to use

eye droppers as a means to deliver

medication to the eyes. Mark

Packer, MD, clinical associate

professor of ophthalmology, Oregon

Health & Science University,

Portland, Ore., USA, also worked

on the fi ndings for the new

technology. Meanwhile, Alan L.

Robin, MD, associate professor of

ophthalmology and international

health, Johns Hopkins University,

Baltimore, Md., USA, weighed in on

what an eye drop delivery system

would need to do to be effective.

Problems with current technology

“If you look at the history

of people trying to develop

alternatives to eye drops, this is

not new,” Dr. Ianchulev said. Over

the years, people have explored

sprays and other ways to get drops

or medication inside the eye

because of the challenges associated

with the eye dropper. One of the

major issues, Dr. Ianchulev said, is

overdosing; this can cause problems

with preservative overexposure of

the ocular surface or in the case of

topical beta-blockers, systemic side

effects such as shortness of breath,

depression, fatigue, and dizziness.

Another problem is that people

often blink while trying to use

eye drops or cannot instill them

directly into the eye. Compared to

oral or intravenous drug delivery,

topical eye drops are notoriously

challenging in terms of dosing

accuracy. What physicians prescribe

is actually quite different from what

people get.

“Eye drops have been around

for hundreds of years,” Dr. Robin

said. “They are a lousy delivery

system for many reasons.” He

said eye drops pose a problem for

those who rely on caregivers to

administer eye drops for them. He

also cited problems of getting a

drop into the eye.

What a new system needsDr. Robin said there several

things a new system would need.

“It has to be relatively inexpensive,”

he said. “It has to be reusable so

that you can put any bottle in it,”

he said, referring to one system that

would take a variety of medications

and refi lls. He said the medicine

would also have to be able to be

administered to the patient without

getting contaminated.

Dr. Robin highlighted the

importance of a patient being able

to use the system with ease. “It has

to have some guidance system, a

focusing light or something that

would allow patients to aim it on

Corinthian Ophthalmic’s Whisper device spray dispenses smaller doses than a generic eyedropper, with controlled dosing and ejection for better accuracy of administration.

Corinthian Ophthalmic’s Whisper device spray dispenses smaller doses than a generic eyedropper, with con-trolled dosing and ejection for better accuracy of administration.

Sean Ianchulev, MD

their eyeball,” he said. There would

need to be a way of administering a

specifi c amount and making sure it

gets to the eye, he said, as well as a

way to keep the eye open.

The new technologyDr. Ianchulev said with the

new technology, one focus has

been improving the directionality

of the fl ow. In addition, speed is

something that was considered

with the new droplet technology.

He said the speed of delivery is

faster than the blink rate, which

would allow the medication to get

to the eye before a person has the

chance to blink.

The LED display improves

positioning and targeting. “They

solve a lot of the issues of how to

deliver medication to the eye and

improve the accuracy and effi cacy

of delivery,” he said.

Examining initial resultsThough still in research

and initial stages, Dr. Ianchulev

said results so far have been

encouraging. “I think it was

surprising to us, the results that we

saw,” he said about presenting some

of the fi rst human data.

Results from just over 100

people compared dilation between

the new technology and the current

eye drop method. Dr. Packer said

with the pupil dilation study it

was not exactly clear what size

dose would work best, so it was

tested with the microdroplets of

1.5 microliters, 6 microliters, and

two sprays of 3 microliters each. He

said all of these quantities showed

effective dilation.

Interest in the technologyDr. Ianchulev said the new

technology is not yet commercially

available anywhere; in terms of

when it will become available, he

said it will likely be different for

each country. “The company is

working on collaborations with the

different pharmaceutical companies

so they can formulate or package

their eye drops with this new

technology,” he said.

“This is the only technology

since several hundred years ago

when people invented the eye

dropper, and we know the eye

dropper has major challenges,”

Dr. Ianchulev said. “So if you’re a

pharmaceutical company, especially

in a very competitive space, that

wants to have a better technology

out there and a differentiated

technology, this could be a huge

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49-50_ EWAP Glaucoma.indd 5049-50_ EWAP Glaucoma.indd 50 21/03/2013 17:2921/03/2013 17:29

51EWAP DEVICES March 2013

When it comes to choosing

instrumentation to make

incisions, variables

between disposable and

reusable blades make a

difference

Disposable or reusable?

Diamond, sapphire,

metal, or silicone?

Depending on the type

of surgery, the amount of surgical

expertise, or the physical location

of the operating room, different

blades have different advantages.

Generally speaking, diamond and

sapphire blades are reusable and

more expensive than their metal or

silicone disposable counterparts. For

some surgeons, the location of the

surgery is the determining factor

about which blade to use.

“In my own practice, I used

to use diamond blades. But at

the surgery center, where there

are multiple users of a single

diamond blade, I started noticing a

signifi cant difference in sharpness

from one day to the next,” said

Ayman Naseri, MD, chief,

Ophthalmology Surgical Service,

San Francisco Veteran’s Affairs

Medical Center, and associate

professor of clinical ophthalmology,

University of California-San

Francisco, Calif., USA. The

inconsistent quality of the diamond

tip “got frustrating,” he said, as

he was forced to change how he

constructed a wound and the

amount of pressure he would use in

a split second.

Although Uday Devgan,

MD, in private practice, Los

Not all blades serve all purposesby Michelle Dalton EyeWorld Contributing Editor


Angeles, Calif., USA, and chief

of ophthalmology, Olive View–

UCLA Medical Center, uses both

a diamond blade and the newer

femtosecond lasers in his practice,

when he’s teaching residents he

prefers they use a steel blade, and

cost is not the main reason.

“With a steel blade, no matter

how sharp it is, there’s a tactile

feedback that is benefi cial to

residents,” he said. “No matter how

sharp the blade is, the incision will

be slower and have more resistance

than with a diamond blade.” Steel

blades “require more effort to enter

the eye,” Dr. Devgan said.

Deciding on blade typeDiamond blades can be too

sharp for a particular incision,

said Steven G. Safran, MD, in

private practice, Lawrenceville, NJ,

USA. He uses a diamond blade for

the paracentesis, when he needs to

use iris hooks, or when he makes

a groove incision for scleral fl aps.

For his main incision, however

(which ranges from 2.2 to 2.8 mm

depending upon which machine

This phaco incision intentionally nicks the limbal vessels to provide better long-term healing. It was created with a femtosecond laser in an anatomic pattern that is diffi cult to replicate with a manual blade.

Source: Uday Devgan, MD

A diamond keratome is used to make a corneal incision. Note the line across the tip of the blade that represents the piercing of Descemet’s membrane. The incision is nearly square with dimensions that ensure optimal sealing, minimal induced astigmatism, and adequate access to the anterior segment during surgery.

While this blade is made of a gem-quality diamond, its thinness causes it to be somewhat brittle, and care must be taken during handling. With proper care, these blades can undergo 1,000 or more uses between maintenance.

he’s using), he prefers metal blades.

“I think it’s easier to make a

well-constructed incision with a

metal blade because diamonds are

actually too sharp,” he said, and

can cut the fl ap on the side. He

prefers a technique of making a

little groove, paralleling the cornea,

and then bevelling down.

At the surgery center, the staff

are “much better at handling the

diamond blades than they are at

the hospital—in the hospital, often

break and are more likely to be

dropped,” Dr. Safran said, adding

those reasons to why he opts

for disposable blades in hospital

settings.

The variability in diamond

blade sharpness at the VA hospital

was also a problem for Dr. Naseri in

training residents. In Dr. Naseri’s

opinion, steel blades offer more

consistency with their sharpness,

and diamond blades can be

inconsistent. The last diamond

blade he used was trapezoidal,

which presented issues with side-

cutting elements in creating a

multiplanar incision.

“Uniplanar incisions that

cut in the same plane don’t pose

a problem for blades with side-

cutting features, but multiplanar

incisions change the plane of the

cut in the cornea,” Dr. Naseri said,

and this can lead to specifi c wound

fl aws.

In resident cases, he has

changed from a multiplanar

incision created with a diamond

blade to a single-plane incision

created with a metal blade. Dr.

Naseri found that the residents

were forced to push too hard with

a dull diamond blade, yet the same

amount of force was problematic

if they were using a sharp

diamond blade. Dr. Naseri said

the consistency of the metal blade

sharpness has improved resident

incision construction.

Dr. Safran typically uses

disposable blades for scleral fl aps,

but likes that a diamond blade can

be used to more easily create a fl ap

that starts at the limbus but moves

away from him. Generally, however,

51-52 EWAP Devices.indd 5151-52 EWAP Devices.indd 51 21/03/2013 17:3021/03/2013 17:30

52 EWAP DEVICES March 2013

New - from page 50Not - from page 51

advantage, particularly, since this

would not require reformulation of

the existing drugs, including those

with higher viscosity.”

Looking to the futureDr. Ianchulev said he thinks the

future looks positive for this sort of

technology. He said it’s important

for physicians to be certain that

patients are getting the medication

prescribed to them.

Dr. Packer agreed that this

could not only benefi t the

administration of drops to the eye

but also the ability for physicians

to track compliance in patients.

“Because this device is electronic

and it’s built like a microprocessor,

it can gather and communicate

information,” he said. “So it would

be possible to track patients’

utilization of their medications.”

Another advantage of the new

technology, Dr. Ianchulev said,

would be that it seems to be fairly

independent of the type of drug

being administered. So far, over

90 drugs have been tested and

worked with it. “You don’t have to

reformulate the drugs,” he said. And

this would be advantageous for the

pharmaceutical companies.

Dr. Packer added that the most

likely form for the technology

would be a cartridge-type system,

which would allow patients to

buy one system and use different

medications in it. “The main thing

is ease of use,” Dr. Packer said. It

has to be easy to use, it has to be

comfortable, and it has to be sterile,

he said. EWAP

Editors’ note: Dr. Packer has fi nancial interests with Corinthian Ophthalmic. Dr. Ianchulev has fi nancial interests with Corinthian Ophthalmic. Dr. Robin has no fi nancial interests related to this article.

Contact informationIanchulev: [email protected]

Packer: [email protected]

Robin: [email protected]

Index to Advertisers

AMO – TECHNIS Family of IOLsPage: 20, 21

www.AbottMedicalOptics.com

Carl Zeiss Meditec AGPage: 35

www.meditec.zeiss.com/ReLEx

MoriaPage: 24, 46

Phone: +33 (0) 146744674

Email: [email protected]

www.moria-surgical.com

Oculus Optikgerate GmbHPage: 11

Phone: +852-2987-1050

E-mail: [email protected]

www.oculus.de

Synergetics IncPage: 2

Phone: +636.939.5100

Fax: +636.939.6885

Email:

[email protected]

www.synergeticsusa.com

Technolas Perfect Vision

GmbH- A Bausch + Lomb

CompanyPage: 14

Phone: +65-6592-0792

www.technolas.com –

www.bausch.com

Topcon Singapore Medical

Pte LtdPage: 39

Phone: +65-68720606

Email: [email protected]

www.topcon.com.sg

Ziemer Ophthalmic SystemsPage: 60

www.ziemergroup.com

ASCRSPage 48, 59

www.ascrs.org

APACRSPage 5, 7, 27, 31, 42

www.2013apacrs.org

World Ophthalmology

Congress (WOC 2014)Page: 57

www.woc2014.org

Dr. Safran prefers metal blades for

lamellar work. He feels it is easier to

stay on plan with a metal blade that

is beveled on one side.

“If the blade is too sharp, it

won’t stay on the plane but will cut

across it,” Dr. Safran said. “It’s like

using a knife for the lasagna instead

of a spatula.”

Pros and consThe positives to choosing a

metal, disposable blade are cost

and tactile feedback, according to

Dr. Devgan. “They’re not nearly

as sharp as a diamond blade, and

you don’t get as clean an incision

as with diamonds. For experienced

surgeons, using a diamond blade is

like a hot knife through butter—

there’s no tactile feedback,” he

said. Diamonds don’t require

routine resharpening, but they are

expensive (running a few thousand

dollars per blade) and are “as fragile

as a potato chip because they’re so

incredibly thin,” Dr. Devgan said.

If surgeons want to change their

preferred incision size from 2.8 mm

to 2.2 mm, the diamond blade can

be rehoned, but if the surgeon opts

to go back to the larger size, a new

blade is necessary, which adds to

the cost as well.

Sapphire blades fall somewhere

between steel and diamonds, Dr.

Devgan said. They’re reusable and

cost more than steel blades, and

while they are less expensive than

diamond blades, they may not last

as long (somewhere in the tens or

hundreds of uses).

“Gem-quality diamond blades

can be used ad infi nitum unless

they’re damaged,” Dr. Devgan said.

The femtosecond lasers offer

an additional type of incision

and while they can create any

architecture design that a surgeon

can fathom, “the fl oor and the

roof of the incision aren’t quite as

smooth as you get with a diamond

blade,” Dr. Devgan said.

Number of usersNewer surgeons should

probably do their fi rst couple

hundred incisions with a metal

blade before trying a diamond.

“Part of any learning

experience is to try all the different

blades,” Dr. Naseri said. “Each

surgeon is going to make his or her

own decisions based on what he

or she likes. I provide my residents

with a rationale about why I prefer

metal blades, but in the end it’s

their decision.”

Dr. Naseri said if he’s the

only user at a surgery center, “I’d

consider the diamond blade, but

only ones without side-cutting

elements. At an institution with

multiple users and trapezoidal

blades, there is just too much

inconsistency.”

Dr. Devgan said he literally has

residents’ hands in his own during

their fi rst few uses of a diamond

blade since the feedback is reduced.

“Whatever blade you use will

ultimately depend on what you are

most comfortable having in your

hands and whether the surgery

center can process it without

breaking or damaging it,” Dr.

Safran said. EWAP

Editors’ note: Dr. Ambrosio has fi nancial interests with Oculus (Lynnwood, Wash., USA). Dr. Fontes has no fi nancial interests related to his comments.

Contact informationDevgan: 800-337-1969, [email protected]

Naseri: 415-221-4810, ext. 4707, [email protected]

Safran: 215-962 5177, [email protected]

51-52 EWAP Devices.indd 5251-52 EWAP Devices.indd 52 21/03/2013 17:3021/03/2013 17:30

53EW NEWS & OPINIONMarch 2013

Rigging the game to win in challenging cataract cases

Practitioners can only

play the cards that they

are dealt in challenging

cataract cases. But that

doesn’t mean that they can’t stack

the deck in their favor. Here’s how

the latest cohesive, dispersive, and

viscoadaptive OVDs can help do

just that.

Bonnie An Henderson,

MD, assistant clinical professor,

Harvard Medical School, Boston,

Mass., USA, believes in planning

ahead particularly in a challenging

cataract case. “I prepare for

challenging cases by thinking

through each step and what type of

viscoelastic may be the best choice

for that action,” Dr. Henderson

said.

Playing a cohesive handShe fi nds that cohesive OVDs

have unique characteristics that

can be very useful in challenging

cases. “Benefi ts of cohesive OVDs

include the ability to maintain

space, clearer visualization, and the

ability to remove the OVD quickly

and easily,” Dr. Henderson said.

One of the strengths of these

cohesive OVDs is their ability to

create space. “Cohesive OVDs,

especially higher molecular

weight OVDs, can be used as a

physical barrier to keep ocular

tissues compartmentalized,” Dr.

Henderson said. “For example,

when attempting to manipulate

the iris during IFIS (intraoperative

fl oppy iris syndrome) cases or

when suturing a PCIOL to the

iris, a high viscosity cohesive can

help compress and isolate the iris

tissue.”

Also, she emphasized, if there

is positive pressure with chamber

shallowing, a high viscosity OVD

will help maintain a formed

chamber and fl atten the anterior

surface of the lens, and this can

help when attempting to complete

a capsulotomy.

For routine cases and for fi lling

the bag, Dr. Henderson’s go-to

OVDs include ProVisc (Alcon, Fort


Switzerland), AmVisc (Bausch +

Lomb, Rochester, NY, USA), or

Healon (Abbott Medical Optics,

AMO, Santa Ana, Calif., USA).

In instances requiring enhanced

stability of the anterior chamber,

however, she will use AmVisc Plus

(Bausch + Lomb) or Healon GV

(AMO).

Dealing out dispersivesLikewise, dispersive OVDs

can play an important role in

challenging cases. “Since they

adhere to surfaces like the corneal

endothelium, these agents protect

against ultrasonic or mechanical

injury,” Dr. Henderson said. She

also fi nds that because challenging

cases tend to take longer, dispersive

viscoelastics can decrease the

amount of corneal damage, as well

as resulting corneal edema.

Another key characteristic of

dispersive OVDs in challenging

cases is their ability to remain in

place. “They do not exit the eye

easily,” Dr. Henderson said. “This

ensures that the anterior chamber

does not collapse prematurely

during an inopportune moment.”

Roger F. Steinert, MD, chair,

Department of Ophthalmology,

University of California, Irvine,

Calif., USA, and director, Gavin

Herbert Eye Institute, sees

dispersives as valuable in situations

where practitioners are concerned

that they’re not going to be able

to ultimately remove all of the

OVD—something that could cause

pressure elevation. “The larger the

molecular weight on average, the

more likely you are to get higher

pressure,” Dr. Steinert said. This

makes a lighter dispersive OVD

an asset in an open capsule case,

where some viscoelastic will be left

behind.

Also in cases involving very

dense nucleus, where there is

often not much of a protective

epinucleus, he fi nds that dispersive

OVDs have a role. During the

second half of phacoemulsifi cation,

the posterior capsule starts to get

exposed and either the phaco tip

itself or a sharp piece of nucleus

can cause a rupture, he warned.

To protect against this, Dr.

Steinert uses a technique that he

dubs the “visco vault.” “As soon

as I can see some red refl ex and

I’ve got enough of the nucleus out

that I can get pretty deep behind

the nucleus, I create an artifi cial

epinucleus with a dispersive

OVD,” Dr. Steinert said. “It can do

a remarkable job in keeping the

posterior capsule back and keeping

it safe.”

Steve A. Arshinoff,

MD, clinical instructor of

ophthalmology, University of

Toronto, explains that by their very

nature, dispersive OVDs, which

demarcate spaces, are used in

more complicated cases. “A space

becomes a complicated case when

you wish to partition the space,”

he said. He pointed to protecting

the endothelium in Fuchs’

dystrophy cases. “What you’re

saying is, you want to partition the

space, the adjacent endothelium,

so that there’s no fl uid fl ow there,”

Dr. Arshinoff said. Likewise, in a

tamsulosin hydrochloride case,

Experts provide OVD cheat sheetby Maxine Lipner Senior EyeWorld Contributing Writer

he stressed, you want to partition

the iris in a way that it doesn’t get

exposed to the fl uid turbulence

and fl op all over the place. In both

cases, a dispersive OVD will remain

in place and provide the needed

buffer.

To maximize effectiveness, he

often pairs the unique properties

of a dispersive agent with those of

a cohesive. He uses the cohesive

agent to induce pressure and the

dispersive to partition space. For

example, for a case involving

a traumatic cataract with two

or three clock hours of broken

zonules, Dr. Arshinoff advised

painting the area with a dispersive

viscoelastic and then putting a

viscous cohesive in the eye to

slowly apply pressure. “Then you

do the capsulorhexis and start

your surgery,” he said. “But before

you try and induce any fl ow in the

eye, you hydrodissect gently and

try to put in a capsular tension

ring in the bag.” This broadens the

shape of the lens so this covers the

disinsertion of zonules. The only

thing in front of the ring is the

dispersive viscoelastic. “The case

then becomes a regular case,” he

said.

For his “go-to” dispersive

agent, Dr. Arshinoff prefers the

original Viscoat (Alcon) to the

others, which he terms copies. “If

it were my mother [as the patient],

I would choose Viscoat just because

we have a longer track record,” he

said. Dr. Henderson likewise favors

Viscoat.

Dr. Steinert has switched

to using the dispersive Healon

EndoCoat (AMO). “What surgeons

are observing is that EndoCoat,

because it is purely hyaluronic

acid, does not have the problem

with viability that some people


53-54 PHARMACEUTICALS.indd 5353-54 PHARMACEUTICALS.indd 53 21/03/2013 17:3121/03/2013 17:31

54 March 2013EW NEWS & OPINION

experience with Viscoat,” he said.

He fi nds that Viscoat tends to be

ropey and disrupts the red refl ex,

while EndoCoat tends to be much

more uniform.

Two aces in the holeMeanwhile, because Preston

H. Blomquist, MD, professor,

Department of Ophthalmology,

University of Texas Southwestern

Medical Center, Dallas, Texas,

USA, always uses dispersive and

cohesive viscoelastics in tandem,

he favors DuoVisc (Alcon). “I am a

great believer in Steve Arshinoff’s

soft shell technique,” he said.

With this, the cohesive viscoelastic

opens up the space in the anterior

chamber while the dispersive agent

helps to protect the endothelium

during phacoemulsifi cation.

Accordingly, he pointed out with

the DuoVisc he gets the dispersive

Viscoat as well as the cohesive

ProVisc. “The DuoVisc is nice

because you have the two separate

viscoelastics that you can put

where you want and have them

function as you want them to,” he

said.

For a complex case of zonular

dehiscence, he fi nds this helps to

simplify the situation. “I want to

use my dispersive viscoelastic to

tamponade the vitreous so that it

has no way to come around the

edge of the lens in the area where

you have zonular dehiscence,”

he said. “Then I put my cohesive

viscoelastic on top of that to

open up the space to perform

the surgery.” Together these each

work to their best advantage, Dr.

Blomquist fi nds.

The viscoadaptive bridgeA fi nal category of OVDs that

can prove helpful in complex

cases is viscoadaptive agents, such

as Healon5 (AMO), which has

characteristics of cohesives and

is also pseudodispersive under

high fl ow conditions. “Healon5 is

called viscoadaptive because under

some conditions it can actually

changes its rheologic behavior,”

Dr. Arshinoff said. “Under high

fl ow conditions it behaves as a

solid, so it starts to fracture apart.”

This makes it a pseudodispersive.

Likewise, when stationary, Healon5

is exceedingly viscous, like a

cohesive, good for maintaining

anterior chamber depth.

One of the strengths of

viscoadaptives, Dr. Arshinoff

stressed, is this viscosity. “They

are so viscous they don’t allow

water to leak through them,” he

said. “So you can use balanced

salt as a second OVD because

the viscoadaptive isolates it

and does not mix with it.” The

viscoadaptive OVD can be used to

block the incision, with a solution

of lidocaine and phenylephrine

serving in place of balanced

salt in the style of the “ultimate

soft shell.” This solution causes

excellent dilation of the pupil and

makes the procedure easier.

When in need of a

viscoadaptive, Dr. Arshinoff favors

Healon5, which he terms the

prototype.

Overall, Dr. Arshinoff

encourages practitioners to look

at each case as if it were involving

physically separable spaces rather

than a single surgical space,

keeping in mind the different OVD

properties. If a practitioner keeps

three or four OVDs on hand, this

can make it easier to deal with

complex cases. “Almost all of them

end up being quite simple because

you have rigged the game for

yourself like a card player who rigs

the cards before he plays,” he said.

“If you rig the game before you

start, things that appeared very

diffi cult really aren’t hard at all.”

EWAP

Editors’ note: Dr. Arshinoff has fi nancial interests with Alcon, AMO, and Bausch + Lomb and has consulted for all of the OVD companies. Dr. Blomquist has no fi nancial interests related to this article. Dr. Henderson has fi nancial interests with Alcon and Bausch + Lomb. Dr. Steinert has fi nancial interests with AMO.

Contact informationArshinoff: 416-745-6969, ifi [email protected]

Blomquist: 214-648-3770, [email protected]

Henderson: 617-723-2015, [email protected]

Steinert: 949-824-0327, [email protected]

Experts - from page 53

DATE MEETING VENUE

April 19-23ASCRS-ASOA Symposium & Congress (ASCRS-ASOA)

www.ascrs.orgSan Francisco, USA

June 27-29

28th Annual Meeting of the Japanese Society of Cataract & Refractive Surgery

(JSCRS)

http://www.congre.co.jp/jscrs2013/english/contents/greeting.htmlTokyo, Japan

July 3-62013 AUSCRS

www.auscrsthemeetingplace.com.auUluru, Australia

July 6-82013 Indian Intraocular Implant & Refractive Surgery Convention (IIRSI)

www.iirsi.comChennai, India

July 11-14 26th APACRS Annual Meeting – A Global Focus on the Anterior Segment

www.apacrs.orgSingapore

July 14-16 An Intercontinental Perspective of Pediatric Ophthalmology & StrabismusSingapore National Eye Centre (SNEC) and AAPOS Joint Meetinghttp://www.aapos.org

Singapore

October 5-9XXXI Congress of the ESCRSwww.escrs.org

Amsterdam, Netherlands

November 16-19 Annual Meeting of American Academy of Ophthalmology (AAO) www.aao.org

Chicago, USA

CALENDAR OF MEETINGS 2013

53-54 PHARMACEUTICALS.indd 5453-54 PHARMACEUTICALS.indd 54 21/03/2013 17:3121/03/2013 17:31

March 2013 55EWAP NEWS & OPINION

MEETING REPORTER

Live reports from the 28th APAO Congress

In addition to its mind-

bogglingly comprehensive

scientifi c program, the 28th

Asia-Pacifi c Academy of

Ophthalmology (APAO) Congress

held in conjunction with the 71st

Annual Conference of the All

India Ophthalmological Society

(AIOS) featured socially relevant

sessions, human interest stories,

and an exploration of trends in

information technology.

India president speaks at Opening Ceremony

With India President Pranab Shri Mukherjee and other

attendee dignitaries lighting a lamp

in an offi cial ceremony to kick

off the 28th APAO Congress, the

meeting got off to a start with a

well-attended Opening Ceremony

that showcased the richness of

Indian culture and history.

“Ophthalmologists have a

special and important status in

society,” said President Mukherjee.

“You are the ones who, by being

doctors, are a critical human organ

that is necessary for the conduct

of human affairs and pursuit of

quality of life. According to the

ancient Indian scriptures, the eye is

the most important of senses in our

body.”

President Mukherjee was

the Chief Guest at the Opening

Ceremony, where he listened

as ICO, AAO, SAO and other

organization offi cials, including

AIOS President Rajvardhan Azad, MD, India, and Frank J. Martin, MD, Australia, discussed

the future of ophthalmology and

its need to address the rising tide

of blindness around the world.

President Mukherjee launched the

digital inauguration of the meeting,

a festival of lights and colorful

videos, with traditional Indian

music highlighting the meeting

location in Hyderabad.

Dr. Martin, outgoing president

of the APAO, said this year’s

Congress should be an excellent

place for attendees to learn.

“We come together at this

Congress from diverse nations with

different beliefs. We have one thing

in common—the preservation

of vision and the prevention of

blindness,” said Dr. Martin.

The Opening Ceremony saw

the awarding of two medals, three

lecture prizes, and three awards.

Women face challenges in ophthalmology

From gender disparities

in healthcare delivery to

potential obstacles in a career in

ophthalmology, women continue

to encounter challenges in the

medical specialty, four women said

at the 28th APAO Congress.

“The only way to change this is

to work together and to hold each

other close, men and women, to

make change over the long term,”

said Lynn Gordon, MD, Calif.,

USA, at the “APAO Women in

Ophthalmology” symposium.

She discussed unconscious bias

and schema and how it impacts

perceptions, including in the hiring

of a man or a woman.

Pearl Tamesis-Villalon, MD,

Philippines, discussed mentoring;

Ava Hossain, MD, Bangladesh,

and president of the SAARC

Academy of Ophthalmology,

discussed gender disparities in

ophthalmology healthcare delivery;

and Anita Panda, MD, Delhi,

India, and incoming president of the

AIOS, discussed potential obstacles

in a woman’s career.

Personal storyDr. Hossain told the story of

the beginning of her career in

Bangladesh. She said that in 1979,

she wanted to enroll in a residency

training program in ophthalmology.

“I went to my professor’s offi ce

and told him what I would like to

do,” she said. “He told me, being a

women, is it possible to be able to

take care of everything [involved in

such a program]? So I decided to do

a fellowship privately fi rst.”

She said that her story is

different from a man’s only because

of her gender, but the situation

in her country is changing—in

1985, there were no women

ophthalmologists, and by 2012,

there were 100. The country still has

a long way to go in gender equality

in the medical profession, she said,

but times have changed since her

professor questioned her abilities in

embarking on her chosen medical

career path.

“Most of all practicing eye

surgeons are still male. But this

will change, as in every successive

year, female ophthalmologists

are increasing, especially as the

older male surgeons are gradually

retiring,” said Dr. Hossain.

Advances neededHowever, women in

ophthalmology still have some

way to go, she said. She cited a U.S.

report that said that white female

ophthalmologists’ mean annual

income was 20% lower than white

males.

She sought to explain this

disparity in terms of how women’s

personal lives can impact their

careers.

“Women ophthalmologists

devote a substantial amount of

their career path time to families

and parenting. Some also work

part time while raising a family. It

is about seeking balance between

career and family [for women

ophthalmologists],” Dr. Hossain

said.

Prevalence of blindness is also

high among women, with women

accounting for more than 64.5%

of all visually impaired people

worldwide—the blind women to

men ratio is 1.43:1.

“In low- and middle-income

countries, men had 1.71 times more

cataract surgery than women. [A

2009 study] estimates that severe

visual impairment could be reduced

by more than 10% if women were

to receive surgery at the same rate

as men,” according to Dr. Hossain.

The women agreed that access

to healthcare is limited to women

and that sociocultural infl uences

can have a major impact on women

both receiving and giving care.

More affordable AMD treatment needed

With nearly 80% of Indians

unable to afford age-related macular

degeneration treatment, including

those who are health benefi ciaries/

government employees, a more

affordable approach to care is

needed, said AIOS President

Rajvardhan Azad, MD, India.

“The need of the hour is

by EyeWorld Staff


055-060 EWAP NEWS & OPINION.indd 55055-060 EWAP NEWS & OPINION.indd 55 21/03/2013 17:3121/03/2013 17:31

March 201356 EWAP NEWS & OPINION

to propose new research by

comprehensive studies to integrate

various components of AMD-

related costs,” Dr. Azad said. “We

need to provide an easy, accessible,

affordable, and effi cacious mode

of treatment. The pricing policy

should not be only profi t-driven but

service-driven [as well].”

About AMDDr. Azad discussed vision and

economics in AMD management at the “Update on age-related macular degeneration” symposium. He outlined the story of AMD, from the epidemiology of the disease—for instance, it is a common cause of blindness in the elderly age group, and the 60+ population is the fastest growing age group in the world. The disease has serious economic ramifi cations for that rapidly growing age group, considerably lowering productivity from work absence, ability to earn a daily living, and reducing quality of life.

The most common severe vision loss in AMD is caused by choroidal neovascular membrane (CNVM), and CNVM’s primary treatment is anti-VEGF, he said.

“In the last 10, 15 years, there’s been a lot of change and a paradigm shift in AMD. For most of us sitting here, the primary treatment is anti-VEGF—others, are laser for extrafoveal CNVM and PDT for a very selective group. We have other treatment that is now historical,” he said. “Therefore, the whole treatment revolves around anti-VEGF.”

Anti-VEGFsAnti-VEGFs have changed the

“aim of therapy … to gain in vision in AMD, where previously the aim in treatment was to maintain vision

or prevent vision loss,” he said.

Therein lies the fi nancial

problem, Dr. Azad said, because

while vision is gained with

the drug, it not only has some

complications, including systemic

and others, as well as issues

involved with frequent visits for

treatments, but it also has the

burden of the cost—the treatment

is expensive.

He compared prices of two

commonly used anti-VEGFs,

Lucentis (ranibizumab, Genentech,

San Francisco, Calif., USA), U.S.

Food and Drug Administration

approved, and Avastin

(bevacizumab, Genentech) used off-

label. The two have similar profi les:

The duration of action for Lucentis

is four weeks, while the duration

of action is four to six weeks for

Avastin, and ocular and systemic

safety is comparable.

But the cost of the two drugs is

signifi cantly different.

“It is 40,000 to 60,000 rupees

per dose for ranibizumab and

2,000 to 5,000 rupees per dose for

bevacizumab,” Dr. Azad said.

The total estimated cost of

anti-VEGFs with a four to six

weeks frequency dosing at 20

expected doses for Lucentis is

800,000 to 1,200,000 rupees,

while Avastin is 40,000 to 100,000

rupees—and another anti-VEGF,

Macugen (pegaptanib sodium, OSI

Pharmaceuticals, Melville, NY,

USA), has a more initial estimated

cost, at 45,000 rupees, going up to

50,000 rupees, totaling 900,000 to

1,000,000 for 20 doses.

Cost burden, protocolAt such costs, it is not diffi cult

to understand how many patients

cannot afford their treatment for

the blinding disease, regardless of

the consequences to their vision.

In his own treatment protocol,

Dr. Azad fi rst diagnoses CNVM/

recurrence and then assigns three

monthly dose treatment of anti-

VEGF with PRN dosing based on

visual acuity, OCT, and fl uorescein

angiography eye test, as needed.

With his current protocol, for

the fi rst year, with 30% to 40%

remission, fi ve doses are expected

when using any of the three drugs,

dropping to four doses expected

in the following years, impacting

cost in a positive way by slightly

reducing the overall fi nancial

burden, he said—but still, that

cost does not account for other

coexistent costs at present, such as

OCT and fl uorescein angiography

eye test.

The future of endothelial keratoplasty

“To understand the future,

you need to understand the past,”

said Jodhbir S. Mehta, MD,

Singapore.

It has been 108 years since the

fi rst penetrating keratoplasty was

performed. Penetrating keratoplasty

became the gold standard for

endothelial replacement, but

even after more than a century

of development, it remains

problematic, including a corneal

endothelial cell loss of up to 70% at

10 years.

The trend today is increasingly

toward targeted replacement of

diseased corneal layers. Endothelial

keratoplasty represents a shift in the

paradigm that has dominated for

almost a century.

However, Dr. Mehta and his

colleagues at the Singapore National

Eye Centre (SNEC) soon found that

the typically shallow Asian eye

presented a particular challenge

to the procedure. Using the taco

folding technique for inserting

donor tissue used in countries like

the U.S., he and his colleagues

were alarmed to fi nd an initial

endothelial cell loss of 30% post-op,

going up to over 60% at one year—

results that were reinforced and

closely replicated in Japan.

They thus introduced the sheets

glide technique. Using the sheets

glide, a large incision, and a pull-

through technique, the SNEC team

was able to reduce the initial loss to

9%, with a clear cornea at day 1.

It still was not ideal—the pull-

through could damage the donor

rim, the sheets glide is open so the

donor tissue is not protected and

may slip, and requires a degree of

ambidexterity.

So the SNEC team developed

the EndoGlide. The earliest

version of the EndoGlide—the

design inspired by thumb drives—

produced double coiling of the

donor tissue, allowing surgeons to

insert larger donor tissues through

smaller incisions. More importantly,

the EndoGlide gave the surgeon full

control of the donor tissue at all

times until insertion is completed.

The EndoGlide reduced one-

year endothelial cell losses from

19% to 15.6%, then 14.9% as they

performed more cases and surgeons

grew more comfortable with the

technique.

The more recent preference for

thinner donor tissue—such as in

Descemet’s membrane endothelial

keratoplasty (DMEK)—led the SNEC

team to develop a new iteration

of the EndoGlide. The EndoGlide

Ultrathin introduces a saddle to

the design to more gently curve the

tissue while loading.

The ideal approach to

endothelial disease, however,

is to cultivate human corneal

endothelial cells.

The fi rst problem was to fi nd a

medium in which cultivated cells

Live - from page 55

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58



would follow the morphology of

normal corneal tissue—with most

media, cultivated cells grow chaotic

and spindle shaped. M5 appears

to be just the medium needed for

the procedure, and now what’s

needed is a carrier—a RAFT (real

architecture for 3D tissue), made of

plastic compressed collagen.

Using cultivated endothelial

cells for treating endothelial disease

remains some years down the

road, but with Dr. Mehta and his

colleagues working on it, the future

of endothelial keratoplasty is just

over the horizon.

Dr. Mehta delivered this year’s

Nakajima Award Lecture in a

symposium on “Current trends in

posterior lamellar cornea surgery: A

revolution in evolution.”

Perspectives on diffi cult glaucoma

The International Academy of

Ophthalmology includes the world’s

senior members of ophthalmologic

academia and was established to

promote academic ophthalmology

and education. One of the strengths

of the Academy is its ability to

draw on experts from a variety of

different subspecialties to offer their

perspectives on issues on which

the discourse might otherwise be

confi ned to experts within a single

specialization.

This was exemplifi ed by the

Academy symposium on the

management of diffi cult glaucoma.

Glaucoma is an

epidemiologically signifi cant

condition in the Asia-Pacifi c region,

one that has wide-reaching effects

on and associations with a variety

of other ophthalmic conditions.

One signifi cant cause of

secondary glaucoma is iridocorneal

endothelial (ICE) syndrome. In this

condition, secondary glaucoma

develops when abnormal cells

proliferate, crossing the Schwalbe’s

line and covering the trabecular

meshwork and obstructing the

anterior chamber angles, said

Dennis S.C. Lam, MD, Hong

Kong, secretary-general of APAO.

In addition, peripheral anterior

synechiae can form.

“On one hand, you have

an open angle component,” he

said. “On the other hand, you

can actually have anatomical

changes, making this a closed angle

situation.”

The treatment options are the

same as for ordinary glaucoma,

although because the ICE syndrome

is progressive, most are only useful

at the beginning. Trabeculectomy,

for instance, is usually successful

only initially, with failure occurring

as early as six months after the fi rst

procedure, said Dr. Lam.

Trabeculectomy fails not only

because of the progressive nature

of ICE, but because of the extensive

fi brosis seen in these relatively

young patients; there can be

aggressive PAS.

“Trabeculectomy will fail

eventually,” said Dr. Lam.

While medical management

and other procedures are successful

in the beginning, Dr. Lam said

that some doctors “want to use

drainage devices as their fi rst line.”

However, the tube is at risk for tip

lumen obstruction by proliferating

abnormal cells, and tube migration

caused by this same proliferation or

PAS formation can also occur.

“If you are using this procedure,

I think it is a good idea to

communicate to your patient that

this may occur and require further

surgery,” said Dr. Lam. As a way

of minimizing or circumventing

this risk, Dr. Lam suggested using a

longer tube shunt. In pseudophakes,

the tube could be placed initially in

the sulcus or pars plana—the latter

case requiring full vitrectomy.

Indian physician sees evolution of ophthalmology in India over long career

When R. B. Jain, MD, Delhi,

India, was 10 years old, he visited

his maternal grandfather on

holiday. His grandfather needed

building materials for a house, so he

asked Dr. Jain to go with him.

His grandfather, a prominent,

well-educated postmaster in his

town in India, was 90% blind from

glaucoma.

He had to hold Dr. Jain’s hand,

and Dr. Jain led him to the shop.

Dr. Jain selected the best wood for

his grandfather. He signed forms to

ensure the wood was delivered.

He was, in essence, his

grandfather’s eyes, and the

diffi culty of the situation, and the

unfairness of it—why anyone would

go blind and be so helpless that

they could not be independent in

such every day activities as walking

or shopping—struck him hard that

day. He made his grandfather a

promise.

“I told him, ‘I’ll be an eye

surgeon,’” said Dr. Jain.

That was 1956. In 1972,

Dr. Jain became qualifi ed as an

ophthalmologist, and he went on

to an illustrious career as a retina

specialist and past president of the

Delhi Ophthalmological Society

and the All India Ophthalmological

Society.

Dr. Jain said he has never

forgotten that day when he pledged

his future career to his grandfather.

“I felt very sad,” he said. “I

thought, why should he be blind?

Why should anyone be blind?

Why should an educated person be

blind?”

He discussed his 40-year

career, and the innovations and

experiences that he has seen as

an ophthalmologist in India in an

award lecture at the Prevalence of

Visual Impairment, Training and

Education in the Asia-Pacifi c Area

symposium.

“It is fascinating to look back at

some of the radical changes during

my career of 40 years,” he said.

#1 pearlsCataract surgery, said

Hungwon Tchah, MD, Seoul, is

essentially nucleus removal—the

rate limiting step, the phase of the

surgery that takes the most time

and effort.

The hardness of cataract is

thus the main factor to determine

the technique to be used during

cataract surgery.

Soft cataracts, said Dr. Tchah,

can be managed by simple

debulking and prechopping. For

harder cataracts, there’s the divide

and conquer technique, and the

phaco chop.

The hardest cataracts, grade

5+, pose a challenge for even

experienced surgeons, but

grooving and chopping work for

these cataracts. However, for such

hard cataracts, even using these

techniques, the increased phaco

energies necessary to emulsify

the nucleus pose a risk to the

endothelium.

For these cases, Dr. Tchah

prefers his own “multichop”

technique.

The principle, he said, is similar

to eating a pizza—it’s diffi cult to eat

a whole pizza until you cut it into

radial slices.

The steps are simple: engage

the nucleus, create the fi rst chop,

rotate and chop, rotate and chop,

etc. Once the nucleus has been

“multichopped” into manageably

sized pieces, the pieces can be

emulsifi ed and removed one at a

time.

This decreases the phaco power

signifi cantly and reduces the risk of

heat damage to the incision, as well

as the potential for damage to the

corneal endothelium.

Dr. Tchah shared his pearl

with attendees at a symposium

titled “My number one pearl in

cataract surgery.” Also on hand

to share their pearls were session

chairs Shamik Bafna, MD,

Cleveland, who described ways to

improve refractive outcomes in

cataract surgery, including using

the ORA system (WaveTec Vision,

Aliso Viejo, Calif., USA); Tetsuro Oshika, MD, Tsukuba, Japan,

who described his technique for

transconjunctival single-plane

sclerocorneal cataract surgery; and

Boris Malyugin, MD, Moscow,

who described his approach

to small pupils, highlighting a

stepwise approach including but

not exclusive to the use of the

Malyugin ring (MicroSurgical

Technology, Redmond, Wash.,

USA). Dr. Malyugin also described

his technique for performing

1.8-mm C-MICS in a vitrectomized

eye. EWAP

Editors’ note: Dr. Mehta is part of the team that developed the EndoGlide, but has no fi nancial interests related to his lecture. Dr. Malyugin is the co-inventor of the Malyugin ring, which he described in one of his pearls. None of the other doctors named in this article have fi nancial interests related to their talks.

Live - from page 56



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2014 APRIL 25–29B O S T O N

Additional Programming

Cornea DayASCRS Glaucoma DayASOA WorkshopsTechnicians & Nurses Program

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Housing OpensFriday, April 19, 2013



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001 COVER EWAP Mar13 VER 1 No9 - APACRSaspx.apacrs.org/apacrs-publication/pdf/Binder Asia Pacific Vol9No1... · Just simply correcting the spherical refractive ... view astigmatism