Mediconcept

Proceedings of

A Standardized Platformand Customized Optics

Hong Kong Seminar 2008

EDITORS

Mr. Charles Claoué

Professor Dr. med. Gerd Auffarth

Mediconcept

Proceedings of

A Standardized Platformand Customized Optics

Hong Kong Seminar 2008

EDITORS

Mr. Charles Claoué

Professor Dr. med. Gerd Auffarth

Library and Archives Canada Cataloguing in Publication

Standardised Platform and Customised Optics (2008 : Hong Kong, China) Proceedings of a Standardised Platform and Customised Optics : Hong Kong

seminar, 2008 / Charles Claoué, Gerd Auffarth, editors.

ISBN 978-1-896825-28-1

1. Intraocular lenses--Congresses. I. Auffarth, Gerd, 1964- II. Claoué, Charles, consultant ophthalmic Surgeon III. Title. IV. Title: Standardised Platform and Customised Optics.

RE988.S734 2009 617.7'524 C2009-900116-0

Mediconcept Inc.

This symposium and proceedings publication has been made possible by a continuing medical education grantfrom Rayner Intraocular Lens Co.

Application and UsageThe authors and publishers have extended every effort to ensure that the application and use of all medical drugsand devices mentioned in this publication are in accord with current recommendations and practices. However, in viewof ongoing research, changes in regulations, and the constant flow of information relating to ophthalmology, the readeris cautioned to consult the package insert of any product for changes, warnings or precautions prior to usage. This isparticularly important when the product is either new or infrequently used.

All rights reservedNo part of this publication may be translated into any other language, reproduced, or utilized in any form or by any means,electronic or mechanical, including photocopying, recording, microcopying, or by any information storage and retrievalsystem without prior written permission from the publisher.

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Mr. Charles Claoué, MA,MD, DO, FRCS, is a cornealfellowship trained ConsultantOphthalmic Surgeon specializ-ing in advanced cataractand comprehensive anteriorsegment surgery, includingrefractive surgery. He is seniorconsul-tant at the Queen’sHospital, London, and inindependent private practice.Mr. Claoué was trained at the

University of Cambridge and at St. Thomas’ Hospital,London and Moorfields Eye Hospital. He has a long-terminterest in presbyopia surgery and advanced intraocularlens design. He is an honorary clinical lecturer to theUniversity of London, Queen Mary College, and honoraryconsultant ophthalmic surgeon to the department ofophthalmology at the Academic University of Pretoria,Republic of South Africa. A member guardant ofthe Worshipful Society of Apothecaries of London,Mr. Claoué is also a Member of the Academy of Experts.He has published approximately 80 peer-reviewed articles.

Dr. Margaret Kearns, MBBS(Sydney), FRANZCO FRACS,practices in Sydney, NSW,Australia. She is a Director ofThe Sydney Eye SpecialistCentre along with herhusband Dr. Richard Smith.The centre is privately ownedand operated by them, withoperating suites for cataractand refractive surgery andextensive consulting facilities

for comprehensive eye care. Dr. Kearns is a Visiting Ophthalmologist at Royal

Prince Alfred Hospital. She has a special interest inrefractive surgery, including measuring visual outcomesand patient satisfaction, and presented papers on thesetopics at the winter meetings of the ESCRS Barcelona2008 and AUSCRS 2008. She has a very long-terminterest in diabetic eye disease and its treatment.

Dr. Brian Harrisberg, MB,BCh, FRACS FRANZCO,Ophthalmic Surgeon, is inprivate practice in Newtown,NSW, Australia and sub-specializes in cataract andrefractive surgery.

Dr. Harrisberg haspublished research papers inpeer-reviewed journals andhas presented lectures inAustralia and at international

ophthalmology meetings and conferences. He is aclinical lecturer at Sydney University and is VisitingMedical Officer and current Head of Department ofOphthalmology at Royal Prince Alfred Hospital.

Dr. Harrisberg is a fellow of the Australia & NewZealand College of Ophthalmologists, a member of theAustralian Society of Cataract & Refractive Surgeons,and a member of the American Society of Cataract &Refractive Surgery.

Contributors

Dr. Guenal Kahraman, MD,obtained his medical degree atthe Ege University, Izmir,Turkey, and his PhD in HospitalManagement at ViennaUniversity of Economics andBusiness Administration. He iscurrently in residency at theDepartment of Ophthalmologyand Optometry of the MedicalUniversity of Vienna. Since 2000, Dr. Kahraman

has worked with Dr. Michael Amon, developer of theSulcoflex™ intraocular lens. His research interestsinclude cataract surgery, biocompatibility of intraocularlenses, and inflammatory diseases of the eye.

Dr. Keiki R. Mehta, MBBS,DOMS, MS (Ophth), DO(Ireland), DO (London),FIOS (USA), is MedicalDirector and Chief of TheMehta International EyeInstitute and Colaba EyeHospital, Colaba, Mumbai,specializing in intraocularimplants, glaucoma, phaco-emulsification, and refractivelaser surgery.

Dr. Mehta has won numerous awards in India andinternationally, including the Triple Ribbon Award of theAmerican Society for Cataract & Refractive Surgery forOutstanding Research presentations in ophthalmology in1998. He has conducted live surgical workshops in everymajor city in India, and has trained thousands of doctorsin intraocular implant surgery and phacoemulsification.

In 2008, he was awarded the Padma Shri Award bythe Government of India for his outstanding contributionto ophthalmology.

Dr. Zhenping Zhang, MD,PhD, is a professor and deputychair of the Department ofCataract Surgery Center,Zhongshan Ophthalmic Center,Sun Yat-sen University,Guangzhou, China. Dr. Zhanghas practiced cataract andrefractive surgeries for over20 years. He has performedover 50,000 cataract surgeries,and has published 90 articles on

cataract surgeries and ophthalmic research. He is a memberof AAO and ASCRS. Dr. Zhang has written two books, andhas contributed five chapters in other publications. His firstbook, Lens Disorders and their Surgical Management waspublished by Guangdong Technological Publishing Housein 2005. His second book, Intraocular Lenses in theRefractive Surgery Era, will be published by People’sHealth Publishing House in Beijing in July 2009.

Contributors

The C-Flex Experience .....................................................................................................................7Zhen-Ping Zhang, MD, PhD

The Use of M-flex™ in Pediatric Cases ............................................................................................9Keiki Mehta, MBBS, DO

Comparison of Toric IOLs ............................................................................................................13Margaret Kearns, MBBS, DO

A Platform for Customized Piggy-back IOL Optics ..................................................................15Gunal Kahraman, MD

Pearls for Successful Implantation of The Rayner T-flex™ Toric IOL ......................................17Brian Harrisberg, MB

IOL Design for the 21st Century: The IOL Platform ................................................................21Charles Claoué, MA, MD

Contents

The C-flex Experience — Zhang 7

slit-lamp camera before surgery. Digital photographswere taken immediately after surgery under a microscopeand photos of retro-illumination were taken by slit-cameraone week and one month after surgery. Fig. 3 presents theresults from 30 eyes. The degree of rotation is roughly1.45 and 1.7 (Fig. 4).

The fourth element Dr. Zhang discussed was PCO.He compared the Rayner 570-C and 570-H intraocularlenses in patients, using E-PCO-2000 software to evaluatePCO score. Fig. 5 shows magnified photos of the Rayner570-H six months after surgery. Dr. Zhang noted thatthere is some cyl indicated. Both sets of PCO scores wereextremely low: roughly 0.021 in the 570-C group, with

The C-flex ExperienceDr. Zhen-ping ZhangProfessor of OphthalmologyZhongshan Ophthalmic CenterZhongshan UniversityGuangzhou, China

Dr. Zhang introduced his topic by stating that in 1995, heused a three-piece AcrySof®. Since 1999, 100% ofpatients have been implanted with foldable intraocularlenses, including hydrophobic, hydrophilic and siliconelenses. However, he recounted that he sought outDr. David Apple in 2001 because of a hydrophilic scare.Some lens discolouring and opacification occurred threeto six months following surgery and some of the lenseswere even explanted from patients’ eyes. Dr. Apple toldhim that the problem did not stem from the doctor butrather, the material. Dr. Apple also disclosed a secret: thebest hydrophilic lens is Rayner.

The objective of Dr. Zhang’s study was to evaluatethe performance and stability of the C-flex® 570-Cintraocular lens with slit-lamp OCT, which recentlybecame available in Dr. Zhang’s center (Fig. 1).

The first issue he raised was centration stability.Cross-sectional images were recorded using slit-lampOCT, one week and one month post-surgery, as depictedin Fig. 2.

Tilt and decentration were measured at vertical andhorizontal meridians with MB-ruler software. The resultsfrom 37 eyes showed decentration of 0.19 mm around thex axis and 0.18 mm around the y axis. The tilt wasapproximately 1° around both the x and y axes, which isquite minimal and may be clinically insignificant. As aresult, Dr. Zhang recommends Rayner C-flex as theoptimal platform for multifocal intraocular lens.

The second element Dr. Zhang pointed out was axisand refraction stability. Anterior chamber depth (ACD)was better with the slit-lamp OCT for evaluation ofstability along the optic axis of Rayner intraocular lens,one day, one week, and one month after surgery.

Also, refractive status was examined for evaluationof refractive shift one day, one week and one month aftersurgery. There was no significant axial shift one day, oneweek and one month post-op. Without ACD, values andrefractive states were extremely stable.

The third element Dr. Zhang mentioned wasrotational stability. Limbus registration was done with a

Fig. 1 Study on Rayner C-flex 570C foldable IOL.

Fig. 2 Examining centration stability.

8 Standardised Platform & Customised Optics

the number in the H group six months post-op showingvery little significant difference.

PCO formation in the C-flex intraocular lens post-surgery seemed significantly lower than that of earliermodels. Dr. Zhang’s conclusion is that the C-flex 570-Cintraocular lens with the enhanced edge seemed toimprove PCO prevention clinically. Dr. Zhang high-lighted that these features can potentially facilitate earlierspectacle prescription and quicker visual rehabilitation forpatients after surgery.

Dr. Zhang concluded by saying that in light of theresults he has seen, he maintains that the Rayner C-flex isan optimal platform for refractive surgeries.

Dr. Claoué noted that in intraocular lens circles,there is always the discussion as to whether one shouldcompare lens PCO by photographic mechanisms, whichare highly scientific, or by YAG capsulotomy rates, whichare highly clinical. His conclusion is that there is no oneright method for doing this, but rather, that they bothallow a valid means of comparing two lenses.

Fig. 3 Rotation: 1 week and 1 month post-op.

Fig. 4 Minimal rotation demonstrated.

Fig. 5 Low PCO score.

The Use of M-flex® in Pediatric Cases — Mehta 9

Dr. Mehta began his presentation by stating that pediatriccataract surgery is a challenging surgery that has changedsignificantly in the past 20 years. He stated that the keyreasons why it has succeeded to such a great extent are,essentially, the better instruments available, the earliersurgery now being performed, and the availability ofhigh-quality, multifocal implants.

Dr. Mehta emphasized the importance of remember-ing a few fundamental facts: the critical period of visualmaturation occurs at the three- to four-month period.Furthermore, an interesting fact was highlighted byDr. Jules Stein, that the ability to see near and at distanceis important for children in order for them to be able todevelop depth perception (stereopsis) and enhancedvisual development.

For a number of years, prior to commencing multi-focal intraocular implants which he had done approxi-mately nine years earlier, Dr. Mehta and his colleagueswere giving varifocal lenses to all children. As he pointedout, it is sad to see a child trying to squint through a pairof bifocal glasses. To his surprise, they found that childrenadapted to varifocality extremely rapidly; there was nevera complaint. As a result, they thought it was an excellentidea and that they should try, in the cases where they werenaturally indicated, to start utilizing multifocal lenses.The surgical plan is the same as always in a bilateralcomplete, or a unilateral complete cataract. Dr. Mehtasuggested that the procedure be performed as soon aspossible, particularly if the visual axis is compromised bya cataract. In children, Dr. Mehta prefers to use generalanaesthesia with positive pressure insufflation, whichresults in a very soft eye, with a deep anterior chamber.He uses a high viscous viscoelastic, essentially, VisCoat®

to do the primary rhexis, although he prefers Healon® atthe time of lens implantation.

ADVANTAGES OF THE M-FLEX®

Dr. Mehta stated that he has used a number of lenses overthe years, predominantly ReZoom® and ReStor®. TheCareGroup out of India made a lens called Prezoil which

was a cost-effective option for disadvantaged patients.However, over the past few months, or in just a little lessthan a year, his team has switched over to the Raynermultifocal lens, which offers several advantages, the keyone being that it has an aspherical, aberration-neutralrefractive optical surface and an enhanced square edge.In children, capsules thicken very quickly and will needto have YAG at an earlier age. Interestingly, one canobserve a certain degree of pseudo-accommodation,which is at the intermediate zone, rather than only atdistance and near.

The question often asked is, “If you were happywith those (ReZoom and ReStor), why did you change?”The reason is that the best diffractive IOLs are only about80-82% efficient, as diffractive optics are associated withan 18-20% contrast loss to higher order aberrations.This can be attributable to reflections and light scatterfrom the facet returns of the diffractive zonal interfaces.The M-flex® does not have this problem and Dr. Mehtastated that he has not had any complaints of unwantedphotopic phenomena.

Physical ocular characteristics are obvious, statedDr. Mehta. Fig. 1 shows the IOL power of the dioptriccarriers. Those are naturally not the powers available topractitioners. What tends to happen is that the axial length

The Use of M-flex in Pediatric CasesProf. Dr. Keiki R. Mehta Professor of Ophthalmology, D. Y. Medical College Medical Director, Chief of the Mehta International Eye Institute Mumbai, India

Fig. 1 IOL power of dioptric carriers.

10 Standardised Platform & Customised Optics

opacify early. He feels that this technique does representa significant difference.

Dr. Mehta described his procedural technique: heperforms the rhexis and uses the hot pulsed BSS from theAqualase at 65º C, which provides an extremely smoothand safe action. As shown in Figs. 2 and 3, he makesstandard side port openings with a diamond knife, anduses a rhexis forceps to swing the rhexis around.Subsequently, after a little hydrodissection in the periphery,he simply moves the Aqualase over the surface. He placesthe tip of the AquaLase in one corner, turns it on, andthe lens literally removes itself with no risk of capsulerupture, even if the chamber shallows. The corticalclean-up is first done with the Aqualase (Fig. 4) andcapsular polishing is recommended, particularly if thereare any residual particles, but more often than not,polishing is not required. Dr. Mehta is very happy with theM-flex multifocal IOL which behaves very well, whereassome of the other lenses have a tendency to vaultanteriorly with positive vitreous pressure tending todevelop a pupillary capture.

is used to roughly evaluate what should be the requiredpower of the patient, but practitioners tend to under-correct by 10%.

In children, capsules thicken very quickly and willneed to have YAG at an earlier age, which is whyDr. Mehta prefers to do a posterior rhexis, conductedduring surgery, which in his opinion is mandatory in allchildren below the age of 12.

Dr. Mehta does not feel that it significantly cuts downthe thickening of the posterior capsule if no blood remainsin the eye following surgery in the post 12 years.

Dr. Mehta uses the Alcon Aqualase® techniquewhich, surprisingly in his opinion, Alcon has discontinued.It uses warm fluid pulses, rather than a high-frequencymechanism. Its greatest feature is that it has a polymer tipat the end, which minimizes the risk of posterior capsulerupture, including the convex posterior capsule ofchildren. The other tremendous advantage is that it tendsto polish the posterior capsule. Dr. Mehta pointed out thathe presented a paper at the ASCRS in 2007 which showsthat this polishing of the posterior capsule with the pulsedwarm water of Aqualase leaves shiny capsules that do not

Figs. 2 Preparation for implantation procedure. Figs. 3 Preparation for implantation procedure.

Fig. 4 Final clean-up with Aqualase. Fig. 5 Multifocal IOL implantation.

The Use of M-flex® in Pediatric Cases — Mehta 11

SPECIAL CONSIDERATIONS IN CHILDRENNaturally, with the Aqualase, the ultrasound part is zero.Dr. Mehta has been utilizing the M-flex for children, andbegins implanting at a very early age. He stated that hehas been doing implants in children from 1976 but for thepast nine years, he has been implanting multifocals; infact, his personal view is that all children should havemultifocals because they work extremely well. In hisexperience, no child has ever complained of flare, glare,double vision, or any other problem.

There are the odd few complications, such aschamber shallowing for the first three days, slight iritis,and an occasional rise in IOP, but this is basically becausesometimes a little viscoelastic is left inside.

Below the age of two, Dr. Mehta has an interestingtechnique. He implants the multifocal IOL to match whatwould be appropriate for the child when he or she growsup, and covers the residual power with a removablepiggy-back HEMA IOL, which is a domed IOL, asdescribed in a paper that he presented at the AmericanAcademy of Ophthalmology three years ago. It issubsequently removed when the child reaches within3 diopters of the approximate power. One does have to besomewhat careful in one’s surgical considerations. Theproblems in pediatrics naturally occur because one ishandling a smaller eye, and there is a tendency forcapsular opacification. However, in a fair percentage ofcases, the children seem to do very well.

Vision in little babies needs to be tested by rolling agraded sized black marble against a black backgroundform various distances and seeing if the child followsit, or by whether or not they can place one object intoanother progressively smaller-sized object. Slightly olderchildren can be asked to read.

Dr. Mehta noted that some of the problems ofsuppression stem from the fact that the children arebrought in a little too late and their parents are skeptical.Furthermore, there are really too many opinions. If theygo to the next doctor who says, “Multifocals in ababy — never do it!” the trouble starts all over again.

Dr. Mehta stated that he does feel that the Aqualaseby Alcon is a good system, especially for thosepractitioners who tend to do implants in a large numberof children.

He also stated that he is very happy with the M-flexfor another reason, namely that the lens doesn’t tendto vault anteriorly. With the IOL in the capsular bag,pressure can be exerted anteriorly by the vitreous face,particularly as the eye attempts accommodation and theciliary muscle contracts. However, as the IOL doesn’tvault, the posterior chamber is always well maintained,which is essential in a child. While Dr. Mehta does tendto be a little more careful with children, if a positiveinsufflation system is used, it is possible to managecomparatively well.

IMPLANTATION TECHNIQUE WITH AQUALASEThe Aqualase requires very little on the part of thepractitioner, particularly in pediatric surgery. Someophthalmologists have commented that they can performthe procedure equally well by using what can be termed a“deplugged phaco.” In other words, no direct suction isapplied and the emulsified lens is expressed via thepressure of the irrigating fluid. In the case of any adherentcapsular remnants, they can be removed and the capsulepolished at a later stage in the procedure. Dr. Mehtaemphasized that it is essential to leave the posteriorcapsule scrupulously clean. At the critical point of lensinsertion, as the leading haptic and optic unfurl, thequality of the Rayner lens can clearly be appreciated as itjust “slips into place” (Fig. 5).

At the conclusion of Dr. Mehta’s presentation,Dr. Claoué stated that he entirely agreed with him in thatit is essential to closely monitor children for emmetropiaas quickly as possible. At a later stage they could haveLASIK, rather than leaving them with a high hyper-metropia leading to suppression. He pointed out to thosewho have not yet used the M-flex that it looks exactly likethe C-flex® as it is based on the same IOL platform.Therefore, if the ophthalmologist has implanted C-flex, itis easy to implant M-flex.

Comparison of Toric IOLs — Kearns 13

Dr. Kearns began her presentation by saying that in June2006, she was very interested to see the advent of toricintraocular lenses. At that time a colleague, who wantedto be spectacle free, approached her for a consultation.He was 59, hypermetropic, with 2.5 diopters of cyl anda thin cornea. In fact, his was the first case in whichDr. Kearns used the Rayner Toric lens. It proved to be agreat success for him, as well as for Dr. Kearns.Subsequently, Dr. Kearns has looked very closely at toricIOLs and has used them to a great extent in her practice.

Dr. Kearns and her colleague, Dr. Richard Smith,have accumulated data on 212 consecutive Toric IOLs.They have used the toric IOL if astigmatism is greaterthan 0.7 diopters as measured by the Orbscan.Specifically, they have been using the Alcon andRayner Toric lenses; Drs. Kearns and Smith assessed therefractive outcomes of these at one month.

Over the past two years, the Alcon lenses havebeen used mainly for the correction of lower levels ofastigmatism, while the Rayner lenses, until recently, havebeen used for correcting higher levels of astigmatism.

Fig. 1 shows the Alcon lenses and the Rayner lensescombined. The orange line illustrates the cornealastigmatism as measured on the Orbscan. With the Alconlenses, the corneal astigmatism corrected was in the lowrange between starting from 0.77 D, whereas the Raynerlenses were used to correct in the range of 2 D up to 14 D.Dr. Kearns pointed out that it was very interesting to notethat the postoperative astigmatism in all of these caseswas much better, on the whole, than preoperatively. Thecombined results of Alcon and Rayner lenses showed that88% of the cases had 0.5 diopters of astigmatism or less;131 with no cyl; 13 with 0.25; 42 with 0.5; 8 with 0.75;13 with 1.0; and 6 with 1.50 (Fig 2).

In Fig. 3, the Rayner final refractive cylinder showsa little more scatter, because these cases start off witha much higher cyl. They are more difficult to measureaccurately on the Orbscan and IOL Master. In addition,some of the astigmatism is not quite regular, and some ofthe corneas are difficult. However, even so, the result wasvery satisfactory.

Comparison of Toric IOLsDr. Margaret KearnsDirector, Sydney Eye Specialist CentreVisiting Ophthalmologist, Royal Prince Alfred HospitalSydney, Australia

Dr. Kearns stated that she agreed with Dr. Zhangthat the toric IOLs are very stable. There were threere-positionings in the group, not because the lenses hadmoved but rather, most likely because in the early casesDr. Kearns was in the process of learning to mark thecornea properly: these re-positionings were the result ofoperator error. There have also been four enhancementsfor low residual errors, among both the Alcon andthe Rayner lenses, which simply reflect a limitation ofthe technology.

Dr. Kearns emphasized the importance of markingthe cornea properly before — and accurately — prior tosurgery. She has developed the technique wherebypreoperatively, the patient sits at a slit lamp. The slit lampcan move — with slits at 10, 20, 30, and other degrees; theslit lamp beam is lined up with the cornea and markedwith a 30 gauge needle. It just pricks the epitheliumto show where the angle of the slit lamp is. Of course, asDr. Kearns pointed out, this is not always possible if thereisn’t a slit lamp in the pre-op room, but the importance ofdeveloping a technique that is accurate for the individualpractitioner is very significant.

Dr. Kearns’s study conclusion is that the performanceof toric intraocular lenses is excellent. Very few refractiveadjustments are needed and there are no major risks.She feels that the Orbscan and IOL Master are accurateindicators of corneal astigmatism, on the whole. Finally,she noted, axis placement is crucial.

Fig. 1 Combined Rayner and Alcon toric IOL results.

14 Standardised Platform & Customised Optics

Dr. Kearns uses toric lenses in 50% of cases, andstated that patient satisfaction has been extremely high inher experience.

Dr. Kearns then entertained questionsfrom the audience:

Dr. Claoué: Do you make any adjustment for the effect ofthe incision?

Dr. Kearns: No, I don’t, because I don’t feel it isnecessary. I don’t make the incision on the steep axis;taking the incision into account doesn’t seem to makeany difference.

Dr. Auffarth: You stated that you use the Orbscan andthe IOL Master for calculating the astigmatism, but thetwo machines use different refractive indices. Do youcompensate for this in the calculation, or is this one of thereasons why you have some slight residual astigmatism?

Dr. Kearns: Those things depend a bit on the case. We’vefound that the Orbscan is more reliable than the IOLMaster readings. We do both, and we often use Pentacamas well. But when you get into difficult corneas, you canfind the measurements you get on the IOL Master,Orbscan and Pentacam can be very different. On thewhole, we use Orbscan, but it isn’t always 100%.

Dr. Auffarth: That’s quite interesting because we aredoing it the other way around. We trust the IOL Mastermore, but we do the measurement of the IOL Masterbefore we do anything else to the eye. This is because anykind of interference - eye drops, for instance - can changethe IOL Master results dramatically. This can greatlyenhance the results of the IOL Master keratometry. Inaddition, topography is always important to exclude anykind of abnormality of the corneal surface. The IOLMaster provides numbers alone and doesn’t show theentire map of the cornea. The two together provide thecomplete picture.

Fig. 2 88% of cases had 0.5 diopters of astigmatism or less. Fig. 3 Rayner: final refractive cyl shows excellent results.

A Platform for Customized Piggy-back IOL Optics — Kahraman 15

A Platform for Customized Piggy-backIOL OpticsDr. Guenal Kahraman Medical University of Vienna Department of Ophthalmology Vienna, Austria

Dr. Kahraman began his presentation by pointing outto the audience that patients have high expectationsafter routine cataract surgery. He stated that, of course,a refractive surprise after cataract surgery is veryunpleasant for the ophthalmologist and extremelyfrustrating for the patient. Despite technological develop -ments and the accuracy of intraocular lens calculations,a pseudophakic refractive error is not a rare event.

Dr. Kahraman then went on to discuss poly -pseudophakia, the situation when more than one intra-ocular lens is implanted in the same eye. This can be doneprimarily, which means that both lenses are implantedduring the same session, or it can be done as a secondaryprocedure to correct pseudophakic ametropia.

In 1993, Guyton et al reported the first implant oftwo intraocular lenses in a capsular bag to achieve highrefractive power, but there were some complications.Inter lenticular opacification pearls and pigment cellswere observed. Also, if two biconvex IOLs wereimplanted in the bag, hyperopic shifts through IOLsurface deformation at the point of IOL contact mightbe seen.

Amon and his colleagues designed a new lens as analternative to laser surgery. Sulcoflex® is intended forimplantation in the ciliary sulcus and is manufacturedfrom a hydrophilic acrylic material noted for its uvealbiocompatibility.

The lens optic has a round edge and a concaveposterior surface (Fig. 1).

Sulcoflex has a 6.5 mm optic with 13.5 mm hapticsand a posterior haptic angulation of 10°. The hapticsfeature a unique undulating configuration, providing verygood centration with rotational stability. Additionally, thesoft haptics and round edges reduce tissue reaction.

In Dr. Kahraman’s pilot study (Fig. 2), there wereten eyes from six patients. Three eyes had the multifocalversion of the Sulcoflex; three eyes had multifocallenses before the Sulcoflex, and four eyes had a Nd:YAGcapsulotomy before the lens implantation.

The patients’ mean age was 56 years and therefractive error was between 2 and +2 diopters. Thepatients were followed for a period of one year. Usinga laser flare cell meter, as well as UBM and Pentacam,photos were made and the investigators measured eyepressure, visual acuity and refraction, the latter of whichDr. Kahraman considers essential. Surgery was doneunder topical anesthesia and piggy-back IOL implanta-tion was performed using the Rayner injector. No intra-operative complications were observed. The resultsshowed that eye pressure was within normal range, witheven less postoperative anterior chamber flare comparedwith that which occurred following regular phaco-emulsification. No iris trauma was observed (Fig. 3).

The results also showed that all the lenses were wellcentered; no rotation, tilt or pigment dispersion wasobserved. All IOLs were in the ciliary sulcus and therewas always a positive iris distance. None of the patientshad optic capture. Uncorrected visual acuity was 0.9 andthe refraction range was +/ 0.25.

Fig. 1 Advantages of Sulcoflex.

16 Standardised Platform & Customised Optics

INDICATIONS FOR THE SULCOFLEX LENSA secondary implantation can be used to correctpseudophakic ametropia. Additionally, with primaryhigh myopic or high hyperopic patients, should theprimary lens of choice not offer a suitably low orhigh power, a Sulcoflex Pseudophakic SupplementaryIOL can be implanted as part of the primary procedure.

In addition, as Dr. Kahraman pointed out, there aremultifocal and toric versions of Sulcoflex.

Pediatric cataract is a further indication for the on going

correction of pediatric pseudophakic changes during thegrowth and development phases of childhood.

Dr. Kahraman concluded his presentation by statingthat his results show that implantation of a secondarypiggy-back Sulcoflex in the ciliary sulcus, leaving theoriginal IOL in place, is an effective, safe and easy treatmentfor pseudophakic refractive errors. The surgery has provento be associated with less trauma, compared with an IOLexchange. Given all this, he contends that Sulcoflexrepresents a new and promising IOL concept.

Fig. 2 Sulcoflex pilot study. Fig. 3 Pilot study result.

Pearls for Successful Implantation of the Rayner T-flexToric IOL — Harrisberg 17

Pearls for Successful Implantationof the Rayner T-flexToric IOLDr. Brian HarrisbergProfessor, Royal Prince Alfred Hospital NSW, Australia

Dr. Harrisberg introduced his topic by saying thatalthough Harold Ridley realized that spherical correctionis needed for best visual outcomes, it has taken so long forthe profession to come to the conclusion that, in fact,more than spherical correction is needed. He noted that itis only now that ophthalmologists are in a position to takeadvantage of cylinder correction; and sphere and cylinderare by far the most important aberrations that lead togood unaided visual outcomes. Dr. Harrisberg feels thatthe correction of aberrations will continue to advanceintraocular lens technology.

ADVANTAGES OF RAYNER TORICSIn the 1990s, Dr. Harrisberg was using the Staar platehaptic IOL for post-keratoplasty patients, or for thosepeople with fairly large amounts of astigmatism. At thattime, the rotation and fitting of the IOL in the bag were aproblem. In fact, as the anterior chamber was hydrated,one could frequently observe the Staar IOL rotation, justthrough the vector forces induced by the irrigating fluid.More recently, Dr. Harrisberg has been using theAcrySof® Toric IOL, one of its advantages being that it isa sticky lens. However, it is very slow to unfold, and it isoften difficult to know when it has reached its endpoint,with the haptic being fully abutted against the equatorialbag. As a result, the surgeon may have finished thesurgery not knowing if the AcrySof IOL has fully opened.Dr. Harrisberg has in the last 18 months been usingRayner Toric IOLs and finds the unfolding characteristicsmuch more acceptable.

THE IMPORTANCE OF CORRECTPRE-OPERATIVE DATASurgical incisional keratotomies are performed forcorneal-based astigmatism where lens surgery is notinvolved. Dr. Harrisberg stated that he has done arcuatekeratotomies and limbal relaxing incisions with cataractsurgery, and these have been only partially successful.Arcuate keratotomies can lead to aberrations; in addition,

limbal relaxing incisions are not always accurate.Dr. Harrisberg noted that he uses a laser (photo-refractivekeratectomy) for corneal-based surgery to correctastigmatism.

The final outcome in cases with toric lenses alsodepends on accurate preoperative assessment. Thesurgeon is armed with a complete medical history anddetermines the patient’s needs and expectations prior tosurgery. The astigmatic data should be accumulated frommany sources, including the spectacle refraction and anyform of keratometry. In addition, Dr. Harrisberg feels thatcorneal mapping is very important.

In terms of the surgery, the only issue being dealtwith is corneal astigmatism. As the crystalline lens isbeing removed, lenticular astigmatism is not a problem.The baseline assumptions in surgery are correctindications and correct refractions. Dr. Harrisbergperforms IOL Master readings first, before the cornealepithelium has been touched, allowing better K readings.He performs manual keratometry and corneal mapping,using the Pentacam.

Rayner, in turn, determines the ideal lens powerand the surgeon makes a choice, depending on whatresidual sphere or cylinder is expected, or what would beacceptable. One must always remember that with this typeof surgery, the sphere and the toric power must be correct,because if one of these is wrong, the patient will bedissatisfied. When the lens is positioned within thecapsular bag, accurate axis positioning is essential.

Dr. Harrisberg cited a study comprising 33 cataractouseyes in patients aged between 56 and 86 years. Four ofthese 33 eyes had keratoconus, and one had a cornealgraft following Zoster keratitis. Approximately 15% ofthese patients had complex or irregular astigmatism.Dr. Harrisberg mainly inserted toric Rayner IOLs with2 diopters of cylinder but noted that in this study thereis quite a power spread, including higher cylinders.Dr. Harrisberg stated that he had seen some seriously sickcorneas, which had been associated with less than perfectresults but overall, achieved a high degree of patient

18 Standardised Platform & Customised Optics

satisfaction. In terms of post-operative target refractions,it should be possible to achieve results within ± 1.0 D butthere are some cases — the extreme astigmats — in whichpatients will still have residual astigmatism.

Dr. Harrisberg contended that visual results willdepend on how much residual cylinder is left behind.Patients having a residual astigmatism of between 1 and2 diopters will usually achieve 6/6 (20/20) or better, whilewith patients having higher cylinders, 9 to 11 diopters,often have best corrected vision of 6/12 (20/40) or better.This appears highly satisfactory to these patients withcomplex astigmatism. However, best-corrected visualacuities (BCVA) are increasingly approaching 6/6(20/20).

Dr. Harrisberg cited a case that occurred about oneyear previously, of a 64-year-old lady. She had beenknown to have had keratoconus since the age of 20 yearsand was wearing contact lenses. She had Map-Dot-Fingerprint corneal dystrophy and recurrent marginalulcers and in the previous four to five years had becomeintolerant contact lenses. She was, therefore, spectacledependent (with a high prescription) and her best-correctedvision was 6/18 (20/16) in both eyes. She was still anindependent lady and driving (with difficulty); however,her vision was not within legal driving limits forAustralia. She had noticed that she was tripping overobjects, at which point Dr. Harrisberg diagnosed cataractwith poorly corrected refractive errors.

Fig. 1A illustrates her Pentacam maps, showing theextensive inferior steepening, irregular astigmatism, andanterior and posterior floats: the patient had keratoconus;her central keratometry readings were 40.5 and 51.However, the equivalent keratometry readings, which takeinto account anterior corneal surface and posterior corneal

surface, are different. Dr. Harrisberg consulted withDr. Claoué as to how best to proceed.

The other eye (Fig. 1B) shows a huge cone, withkeratometry readings of 43.8, 51.6, but the equivalent Ksare smaller. Dr. Harrisberg decided to use the equivalentKs, aiming to correct the absolute center of the cornea.The surgical team had to choose one point and base theirkeratometry data on it. Using the equivalent Ks, theydesigned a custom-made lens, 13 diopters for the sphere,9 for the cyl, 12.5 diopters for the sphere and 11 for thecyl in the other eye; and chose the axis according to all thedata available. The patient’s pre-operative BCVA was6/18 (20/60) best. Her post-operative vision was 6/15(20/50) and 6/12 (20/40) unaided.

Although she had some residual cylinder, she wassatisfied with the result having achieved independentunaided vision and best corrected 6/6 (20/20) vision. Anabnormal cornea requires a high cylindrical correctionand can achieve very good results, especially withaccurate data and confidence in this data.

WOUND CONSTRUCTIONDr. Harrisberg highlighted the importance of woundconstruction. He stated that if a lens is going to move atany time, it’s going to move in the first one to four hoursbecause that’s when the chamber will shallow if there ispoor wound construction. What’s more, he stated, a lenscan tilt, possibly inducing coma, or it may rotate which,in the case of a toric lens, will change the astigmaticcorrection. In addition, the capsulorrhexis size is importantbecause one wants stability within the capsular bag.Cortical clean up is also essential because one doesn’twant anything to displace the lens in any way.

Figs. 1A, B Pentacam maps OS and OD in a patient with keratoconus.

A B

Pearls for Successful Implantation of the Rayner T-flexToric IOL — Harrisberg 19

technique in the long axis, to facilitate aspiration frombehind the lens, as this technique is less likely to causerotation.

After once again confirming the correct axis, theprocess is complete.

The lens is deemed to be sitting perfectly, with goodoverlap between the capsulorrhexis rim and the optic,and on the aligned axis. Dr. Harrisberg always hydratesthe incisional wound and the side port incision - to ensurea seal.

ADVERSE OUTCOMESIf the lens is incorrectly positioned, the outcome willobviously be unsatisfactory. It is also important to notethat the higher the power of the lens, the more sensitivethe visual outcome will be to axis alignment.Dr. Harrisberg related that as he once observed anentrapped trailing haptic that was captured by the plunger,care must always be exercised in loading. However, asMr. Claoué pointed out, the injector plunger cannot beexpressed through the cartridge and an entrappedhaptic will require the lens and injector to be removed asone unit.

In concluding his presentation, Dr. Harrisbergstated that the Rayner T-flex compares favorably withother toric IOLs. It provides a high degree of certainty inmaintaining the position of the axis of the lens; the lenssits exceptionally well within the capsular bag, and itdelivers safe and accurate outcomes.

MARKING TECHNIQUESThe pre-operative marking of the cornea is done with thepatient sitting and focusing in the distance. Topical anes-thetic drops are then administered and Dr. Harrisbergmakes one marking pen spot to indicate the six-o’clockand nine o’clock position. Sometimes, these marks maynot always be accurately placed, and the surgeon isadvised to stand back from the patient to assess themarked axis relative to the vertical meridian.

MAJOR ELEMENTS OF SURGERYThe loading of the lens is done by the technicians. It isimportant to load the lens in a reverse-S configuration toensure that it enters the eye for positioning within thecapsular bag with the correct orientation. As the injectorwings are closed, it is important to check and double-check that the haptics have not been captured within thewings of the cartridge.

The injection process is extremely simple: the lensexits the injector nozzle safely and in a controlled manner,without “shooting,” before quickly unfolding within thecapsular bag.

There are two diametrically opposed axis markingson the anterior IOL surface which indicate the IOL axis oflowest power. This is intra-operatively aligned with themarked axis of highest corneal power.

Once the lens is well positioned, it is essential toremove all residual viscoelastic from in front, as well asfrom behind, the lens. Dr. Harrisberg suggests using a tilt

IOL Design for the 21st Century: The IOL Platform — Claoué 21

IOL Design for the 21st Century:The IOL PlatformMr. Charles ClaouéConsultant Ophthalmic Surgeon, The Queen’s Hospital, LondonHonorary Consultant, Dept. of Ophthalmology, Academic University of PretoriaHonorary Clinical Lecturer, University of LondonConsultant to Rayner Intraocular Lenses Ltd.

With reference to the title of this Symposium,“A Standard Lens Platform and Customized Optics,”Mr. Claoué stated that he favors it because he believe it’sthe direction in which intraocular lens design is going tobe heading over the next few years.

Mr. Claoué began his presentation by posing thequestion, “What is an intraocular lens platform?” It is, hestated, everything except the “optics of the optic”.This immediately posed a terminological problem, in thatthe word “optic” refers both to a part of the lens and to itsfunctional performance with light.

He contended, quite clearly, that what is requiredis a foldable lens. The three materials traditionally usedare silicone, hydrophobic and hydrophilic acrylics. Whileall of these materials have strengths and weaknesses,Mr. Claoué’s lecture highlighted the fact that if a givenpatient requires VR surgery with silicone oil and has asilicone IOL implanted, there will be 100% silicone oilcoverage of the lens, which obviously destroys theefficiency of the optic. This is not a problem withhydrophilic acrylics.

THE DIFFERENCES BETWEEN HYDROPHOBICAND HYDROPHILIC IOLSManufacturers of hydrophobic acrylics claim that theirlenses are superior. However, independent assessment hasdemonstrated that they are associated with 35% siliconeoil coverage, which is still unsatisfactory. In fact, it’s onlywhen hydrophilic acrylics are used that one can achieve anacceptably low silicone oil coverage of less than 5%.However, hydrophilic lenses have two unique advantages.The first is that they are the only materials capable of actingas a drug delivery device, by utilising a “sponge effect”.Mr. Claoué stated his belief that in the very near future —perhaps within the next five years — practitioners will beable to soak lenses in antibiotics, in drugs to inhibit PCO,in anti-inflammatory drugs, and perhaps more.

The second advantage is that hydrophilic acrylicsare the only IOL materials existing in two states, the

hydrated state, which is used in surgery, and thedehydrated state which can be lathed during manufacture,using computer-guided, diamond-tipped lathes, intoextremely complex optical forms. This cannot be donewith compression molded lenses, as they would require anew mold for each optic. As IOL practice moves towardfully customized lenses, this material is going to be theonly viable one.

Mr. Claoué noted that several years ago, there wereperceived problems with hydrophilic acrylics, several ofwhich had opacified. Some of these lenses were beingmade from unsuitable materials which had been co-polymerized in the form of rods instead of as individualdiscs. This had posed manufacturing problems, particularlyin terms of regulating the temperature of what is a highlyexothermic reaction. This resulted in non-uniformity ofthe porosity of the co-polymer matrix, which contributedto the problem. Another such lens was the HydroView®

which as Mr. Claoué remarked, many people in theaudience may have actually used. The manufacturers ofthis lens had encountered an unexpected interaction due tothe presence of silicone in the packaging material.However, Mr. Claoué noted that the Rayner hydrophilicacrylic material had existed for ten years and it had neveropacified in any normal eye.

Indeed, Mr. Claoué said, all materials can have thepropensity to opacify in the eye under certain conditions.Even PMMA, the gold standard, has been known toopacify, as have some hydrophobic acrylics. As a result,one must not think that hydrophilic was historicallyunique in this respect. Rayner has never had any lenscalcify in a normal eye, which they contend is the resultof quality control, a statement Mr. Claoué finds credible.

In terms of IOL construction, one-piece lenses arepreferable for several reasons. Manufacturers like thembecause they’re cheaper to make but unfortunately, theydon’t always pass on the low price to ophthalmologists ortheir patients! However, the ease of injection is so muchgreater with one-piece lenses compared with three-pieceand Mr. Claoué believes that three-piece lenses willbecome a thing of the past fairly quickly.

22 Standardised Platform & Customised Optics

RAYNER C-FLEX® IOLAs Mr. Claoué travels around the world, he sees anincreasing number of copies of the Rayner C-flex lens —clones, one might say — but only one, the Rayner C-flex,is an FDA-approved lens. Indeed, it was the firstnon-American lens to have been approved by the FDA forover two decades.

The Rayner C-flex lens is provided with a single-use,disposable injector (one free with every lens) and it ispossible to achieve an implantation through a 1.8 mmincision using a wound-assisted technique. It has a softplunger tip that completely occludes the lumen of thenozzle to help prevent IOL capture during injection anda round nozzle profile with a parallel-sided distal tip.This facilitates insertion of the nozzle tip into the eyewithout stretching the wound, helping contribute to amuch safer procedure.

A viscoelastic is sparingly applied to the injectorloading bay and nozzle. The lens is then placed centrallywithin the loading bay, taking care to ensure that it is welltucked under the flanges and the loading bay is closed,ready for injection. Mr. Claoué finds the entire processextremely quick and easy.

THE CRITICAL ROLE OF HAPTICSHaptics are probably the most “boring” part of the lensand they don’t attract much attention from ophthalmolo-gists. However, they are critical because they are the partof the lens that provides stability. As more complexoptics are developed, this stability becomes even morefundamental because without perfect stability, the opticssimply will not work. Mr. Claoué pointed out that the

Rayner haptics are of a special closed-loop designincorporating Rayner’s Anti-Vaulting Haptic, or AVH™,Technology (Fig. 1) which helps provide excellentcentration with superb stability. Centration and stability isalso enhanced by the lens having zero haptic angulation.

Rayner C-flex® IOLs are intended for in-the-bagplacement but are also suitable for ciliary sulcusplacement in normal eyes. A larger version of the lens,Superflex®, is also available which is especially suitablefor the larger myopic eye.

Professor Gerd Auffarth (Heidelberg, Germany) hasalso clinically evaluated the performance of the uniqueRayner haptic design and has concluded that it is a verystable lens. Furthermore, he demonstrated remarkablerotational stability indicating its use as a toric.

In terms of which other features are desirable, onewants absolutely minimal PCO. Mr. Claoué’s studies haveshown that at 30 months the Nd:YAG rate is less than 2%.This is because of Rayner’s Enhanced Square Edge™

(Fig. 2) which is characterised by the square edgecrossing the haptic-optic interface. If there isn’t a squareedge at the interface, then there is an “Achilles heel” inthat lens cells can migrate to the visual axis. In fact, thesquare edge is more important than the material for

Fig. 2 Minimal PCO due to Enhanced Square Edge.

Fig. 3 Lack of square edge doubles YAG capsulotomy rate.

Fig. 1 Table centration.

IOL Design for the 21st Century: The IOL Platform — Claoué 23

PCO prevention; this has been shown in human andanimal models.

Fig. 3 shows YAG rates at 6, 12 and 18 monthsfor another three-piece and single-piece lens design.The fact that there is no square edge doubles the YAGcapsulotomy rate. So actually, the way the manufacturersmake the lenses, in terms of design, does directly impacton patient outcomes.

THE EFFECTS OF IOL COLORThe majority of studies show no link between blue lightand retinal disease; it’s UV and violet light that matter.Blue light is needed for good vision and for circadianrhythm to ensure a good sleep cycle and well-being. However, yellow lenses are popular with someophthalmologists because of their perceived advantage ofblue-light blocking. Mr. Claoué expressed his opinion thatyellow lenses are a marketing tool that has been used togreat effect, but that their popularity has not been basedon any evidence. He contended that at this point, in the21st century, ophthalmologists should be practisingevidence-based medicine. One very prominent European

ophthalmologist is explanting yellow lenses fromdepressed patients, such is the concern about the effect ofblue light on circadian rhythms.

Summarizing the features of the Rayner C-flex,Mr. Claoué pointed out that it is foldable, injectable and isprovided with a single-use injector. It is available in alarger size for myopic eyes, features anti-vaulting hapticsfor centration and stability and has an enhanced squareedge for low PCO. It is manufactured from a hydrophilicacrylic material for biocompatibility and has excellentresistance to silicone oil adherence.

In conclusion, stepping back to look at the largerpicture, Mr. Claoué highlighted the impact of IOLimplantation by hypothesizing a scenario in which apatient returns to their ophthalmologist and claims, “I cannow see!” Naturally, the patient is very happy but thatlevel of happiness may be quite out of proportion withhow well they can actually see. Mr. Claoué contendedthat in operating on people’s eyes, ophthalmologistsactually operate on much, much more, and give patientsa new lease on life; this is, in fact, why patients areusually so happy.

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