Multifocal IOL Basics

REFRACTIVE DIFFRACTIVE

Concentric zones:

M-flex (Rayner)

Segmented:LENTIS Mplus (Oculentis)

Progressive:

677MY (Medicontur)

Bifocal: IQ AcrySof ReSTOR (Alcon)

Trifocal: FineVision (PhysIOL)

Extended Depth Of Focus (EDOF):Tecnis Symfony (AMO)

Types of Multifocal Designs

Success of Multifocal IOLs

IOL• Material

• Chromatic aberration

• Technology• Bifocal, trifocal, progressive• Customize..• Exact sizing/refraction

• Precision (halos, glares)

• Light utilisation (contrast)

• DESIGN - PCO protection

PATIENT SELECTION• Eye

• Anatomy (aberrations, astigmatism, kappa angle)

• Retina • Anatomy (esp. macula)

• the first place /neuro-receptor of receiving signals

• Pupil• Dynamic pupilometry

• Brain• Neuroadaptation?

• Cognitive function – cognitive tests?

(METROVISION)

Neuroadaptation?

Despite the fact that it is generally accepted that the brain plays a major role in visual performance with these more complex intraocular lenses, which is referred as neuroadaptation, there are no studies available evaluating cortical activity in the presence of multifocal lenses

Rosa AM, BioMed Res, 2013

Why does it seem that neuroadaptation differs in different IOLs?

Role of Retina in transferring the input

RETINA = 1st CONTACT - PHOTORECEPTORS

• Colour, depth, shape, motions = encoded by photoreceptors of few hundred microns of retinal thickness

• Incoming visual signals are processed by at least 80 neural cell populations and 20 separate channels within the retina

• Visual information leaves the retina through 20 different channels

• The cortex extracts the relevant information from the retinal input

• Visual input is initially encoded in the retina in two dimensions: light & intensity

Jonathan J Nassi & Edward M. Callaway:

Parallel Processing Strategies of the Primate Visual System;

Natur reviewes, Neuroscience

Success of MF –Neuroadaptation or IOL (design, material)

The better the transfer of information from the retinal photoreceptors through the ganglion cells to the brain –i.e. better output (less work for brain) – the better the

toleration of patients – quicker “ neuroadaptation”

OPTIC is CRUCIAL

= IOL

ZOOM ONDIFFRACTIVE OPTICAL PRINCIPLES

DIFRACTIVE OPTICAL PRINCIPLES

• Diffraction refers to various phenomena which occur when a wave encounters an obstacle.

• = bending of waves around small obstacles and the spreading out of waves past small openings

• As the waves spread out into each other, constructive and destructive interference occurs

Geometric and Diffractive Optics

A simple refractive lens can be described

mathematically with geometric optics.

The dimensions of an IOL is several orders of

magnitude higher than the light wavelength.

DIFFRACTION

IS NEGLIBLE

Due to the wave-like behaviour of the light, the more

precise mathematical description is given the

diffractive optics.

The diffraction can not negligible if in the presence of

small obstacles or slits in the light path.

Effect of Diffractive Elements

2nd

diffractive

order

1st

diffractive

order

0th

diffractive

order

The diffraction is increasing if the dimensions of the microstructure and

the light wavelength can be found in the same order of magnitude.

Theoretically, infinite

diffraction order is

generated.

The enhanced diffractive

orders can be chosen with

the microstructure design.

For example:

Enhanced 0th and 1st orders

provide a bifocal IOL.

Comparison of a Monofocal (Refractive) and a Multifocal (Diffractive) IOL

Monofocal (refractive) IOL Multifocal (diffractive) IOL

MTF through-focus performance: MTF through-focus performance:

Distance

vision

Near

vision

Distance

vision

Connection Between Diffractive Orders and Additional Dioptric Powers

1st diffractive order Padd

2nd diffractive order 2 × Padd

3rd diffractive order 3 × Padd

1.08 D

2.17 D

3.25 D

Padd is designed by the diffractive structure

. . . . . .

0th diffractive order 0 0 D0th order normally

provides the far vision

(„refractive” focal point)

EXAMPLE:

Basic Structure of a Diffractive IOL

DIFFRACTIVE ARRAY

MONOFOCAL / TORIC LENS

MULTIFOCAL /

MULTIFOCAL-TORIC LENS

+

=

Key Parameters for Diffractive Design

When dealing with a diffractive optic these must be considered:

The reference wavelength is 555 nm (green): the peak of photopic sensitivity of retinal cells

Reading (vision) distance is determined by the additional dioptric:

Reading (vision) distance(s) ~ addP

1

Additional dioptric power [D] Reading (vision) distance [cm]

1.75 80

2.17 60

3.50 40

Examples:

Diffractive Structure Characteristics

STEP HEIGHT determines

energy distributionbetween far and additional

focal points

Diffractive Structure Characteristics

STEP WIDTHdetermines

additional dioptric power(the higher the addition the more frequented the diffractive rings)

Trifocal Diffractive Structure Design(FineVision)

1st diffractive structure:

Padd = 3.50 D

2nd diffractive structure:

Padd = 1.75 D

0th order: FAR

1st order: NEAR (3.5 D)

2nd order: NOT USABLE (7.0 D)

0th order: FAR

1st order: INTERMEDIATE (1.75 D)

2nd order: NEAR (3.5 D)

+

=Superimposed structure:

2nd order of the 2nd diffractive structure coincides with the 1st

order of the 1st diffractive structure

International patent ID: WO2011092169(A1) (assignee: PhysIOL)

Quadrofocal Diffractive Structure Design(PanOptix)

Four consecutive diffractive orders:

0th 1st 2nd 3rd

Corresponding dioptric powers:

0 (far) +1.08 +2.17 +3.25

1st diffractive order (+1.08 D) is suppressed

US Patent ID: 9335564 B2 (assignee: Novartis AG)

Apodization of a Diffractive Structure

Before apodization Apodized structure

Apodization:

Decreasing steps height

from the centre to the

periphery

Effects of Apodization

• Pupil-dependent light intensity distribution between the far andadditional focal points.

• Reduced light losses.

• Additional focal point or points are suppressed at large aperturesto decrease risk of dysphotopic effects (for instance: halo).

Chromatic Aberration & DIFFRACTIVE OPTICs

An important issue with diffractive optics is chromatic aberration.

WHY?

Basics of Chromatic Aberration

Chromatic aberration is occured by the

wavelength dependence of the refractive indexDifferent wavelengths are

focused to different focal points

Chromatic

blur

Bi-Flex 677MY is made by

Benz 25, hydrophilic acrylic material

having low chromatic aberration

(ABBE NUMBER: 58)

Chromatic Aberration of a Diffractive IOLin the Human eye

Far focal point: The larger

wavelength, the lower dioptric

power due to the positive chromatic

aberration of the imaging ocular

tissues.

Additional focal point: Slight

chromatic shift due to the opposite

polychromatic characteristics of the

human cornea and the wavelength-

dependence of the near focus.

ZOOM ON…..

Bi-Flex M

• diffractive–refractive design concept to provide improved control energy distribution

• 7 diffractive discontinuities, or steps, that have been incorporated in the anterior surface of the acrylic optic to provide the diffractive added power

• apodized diffractive optic design

• apodization improves image quality by optimizing light energy delivered to the retina by distributing the appropriate amounts of light to near and distant focal points, regardless of lighting situation.

Anterior

Apodized

Optic

6 mm

Aspheric Optic

(neutral approach)

6 mm

Biconvex

Optic

13mm

Bi-Flex M Technology

Central 3.0 mm

apodized diffractive

structure

Step heights decrease

peripherally

from 2.2 – 1.4 microns

+3.5D at lens plane

equalling +2.7D at

spectacle plane

Outer refractive zone

Aspheric (neutral approach)

Examples for Diffractive Multifocal IOL

Alcon AcrySof IQ PanOptix (non-apodized trifocal; Padd = 2.17 / 3.25 D)

Alcon AcrySof IQ ReSTOR (apodized bifocal; Padd = 2.5 D; 3.0 D)

AMO Tecnis Symfony (non-apodized EDOF; Padd = 1.75 D)

PhysIOL FineVision (apodized trifocal; Padd = 1.75 / 3.50 D)

Zeiss AT LISA tri (non-apodized trifocal; Padd = 1.66 / 3.25 D)

Characteristics:

• Very good far vision

• Very good near vision

• Insufficient intermediate vision

• Dysphotopic effects (halo, glare) depends on the diameter of the diffractive optics

• Chromatic aberration depends on the Abbé-number (the higher the Abbé-number, thelower the chromatic aberration)

• 0th and 1st consecutive diffractive orders are used generally (reduced light loss)

Bifocal IOLs – Clinical Aspects

0

0,2

0,4

0,6

0,8

1

1,2

1,4

Characteristics:

• Compromised good far vision

• Compromised good near vision

• Sufficient intermediate vision

• Dysphotopic effects (halo, glare) depends on the diameter of the diffractive optics

• Chromatic aberration depends on the Abbé-number (the higher the Abbé-number, thelower the chromatic aberration)

• 0th and two consecutive diffractive orders are used generally (reduced light loss)

Trifocal IOLs – Clinical Aspects

ASSESSMENT OF OPTICAL QUALITY

• MTF means how faithfully the lens reproduces detail

from the object to the image produced by the lens.

Modulation Tranfer Function

Transmitted contrast 100%

Transmitted contrast 50%

Transmitted contrast 2%

MTF = 1

MTF = 0.5

MTF = 0.02

MTF through-focus Performance ofBi-Flex 677MY and FineVision

MTF means how faithfully the lens reproduces detail from

the object to the image produced by the lens

Measurements performed for a spatial frequency of 50 lp/mm

according to the related ISO standard

Progressive Apodized Diffractive (PAD) Structure on Bi-Flex 677MY

• Reduces light loss

• Reduced risk of dysphotopic effects

• Enhances depth of focus(PROGRESSIVE VISION within full accommodative range)

• Improves the distance vision at large pupil apertures

Progressive apodization:

Bi-Flex M - Progressive IOL

Normal diffractive array

The diffractive / progressive matrix increases the depth of field of the near vision distance vision. (b). The

curves overlap in defocus the intermediate vision zone with a defocus of 1.5 dpt (67cm).

distance near

Characteristics:

• Very good (not compromised) far vision

• Very good near vision

• Competitive intermediate vision with trifocal IOLs

• Low level of photopic phenomena thanks very high Abbe number (58)

of the material and precision of diffractive steps

• Quick neuroadaptation

Bi-Flex M: PAD

Progressive Apodized Diffractive (PAD) Structure on Bi-Flex 677MY

Bi-Flex 677MY Bifocal competitor

Sub-micrometer

manufacturing precision:

• reduced light loss

• less dysphotopic effects

ZOOM ON…..

Bi-Flex M

• diffractive–refractive design concept to provide improved control energy distribution

• 7 diffractive discontinuities, or steps, that have been incorporated in the anterior surface of the acrylic optic to provide the diffractive added power

• apodized diffractive optic design

• apodization improves image quality by optimizing light energy delivered to the retina by distributing the appropriate amounts of light to near and distant focal points, regardless of lighting situation.

Anterior

Apodized

Optic

6 mm

Aspheric Optic

(neutral approach)

6 mm

Biconvex

Optic

13mm

Bi-Flex M Technology

Central 3.0 mm

apodized diffractive

structure

Step heights decrease

peripherally

from 2.2 – 1.4 microns

+3.5D at lens plane

equalling +2.7D at

spectacle plane

Outer refractive zone

Aspheric (neutral approach)

• PCO is limiting factor of success of multifocal IOLs

• PCO rate finally makes a difference in outcomes and patient satisfaction

• PCO prevention is more important for patients receiving multifocal IOLs

because of their increasing visual demandsBi-Flex M

• r = 10microns

• Polish free technology

Bi-Flex M and PCO

A unique & patented design

With 180° total contact angle with capsular bag equator

Medicontur Bi-Flex Average contact angle: 88.8°

Competitor 1Average contact Angle: 69°

Experimental simulator with a diameter of 9 mm

Competitor 2 Average contact Angle: 64.4°

Natural Yellow Filter+

• for FILTERING AS MUCH AS NECESSARY

for PRESERVING AS MUCH AS POSSIBLE

Medicontur natural yellow filter protects the macula against the wavelengths comprised between 390nm and 460nmthus covering the whole most dangerous zone of « blue light » and maintaining scotopic vision (over 460nm)

Bi Flex M yellow filter

MEDICONTUR

Natural

Yellow filter

Simulation of vision without and with yellow filter+

IOL

With NON natural

Yellow filter

IOL

With NO

Yellow filter

WHAT ABOUT THE MAIN COMPETITORs ?

Examples

• Trifocal, non-apodized: AT LISA tri (Zeiss): +1.67D, +3.33D

• Apodized bifocal: ReSTOR (Alcon) +3.5D or +3.00D

• Apodized trifocal: FineVision (PhysIOL): +1.75D, +3.50D

• Quadrifocal, non-apodized: Panoptix (Alcon): +2.17D, +3.25D

ZOOM ON THE MOST IMPORTANT MARKET PLAYERS…

TRIFOCAL

AT LISA TRI & PHYSIOL

PanOptix

Symfony

Reading

Contrast sensitivity

Alcon material

problems

FAR & INTERMEDIATE

No near vision

Contrast sensitivity

TRIFOCAL PANOPTIC SYMFONY

0,00

0,50

1,00

1,50

+4,0 D +3,5 D +3,0 D +2,5 D +2,0 D +1,5 D +1,0 D +0,0 D -0,5 D -1,0 D -1,5 D -2,0 D -2,5 D -3,0 D -3,5 D

Defocus curve - 6M

677MY

Based on clinical observation – Bi Flex M shows clinically clear trifocal performance

ZOOM ON…..

CLINICAL FEEDBACKS

Clinical Studies at Glance

9 countries2 continents 14 surgeons

3 prospective

study3 „prospective“

study

Quick

evaluation

results

Review of the Co-operating surgeons and Number of Operated Patients / Eyes

STATECENTRUM /

SURGEON

No of

patients

No of

eyes

GERMANY

AK Bellevue 26 52

Prof Böhnke 12 15

Dr Dörner 7 14

Dr Kohm 6 12

HUNGARY

Prof Nagy 54 108

Dr Gyory 50 100

Dr Nagymihaly 63 126

CZECH REPUBLIC Prof Pasta 10 20

STATECENTRUM /

SURGEON

No of

Patients

No of

EYES

SWITZERLAND Dr Sutter 5 10

ISRAEL Prof Zadok 10 20

SPAIN Baviera Group 4 8

PHILIPPINES Dr Naval 16 31

FRANCE Dr Assouline 100 200

AUSTRIA Prof Grabner 10 20

BELGIUM Dr Van Acker 35 70

TOTAL No of patients 393

No of eyes 786

-

0,20

0,40

0,60

0,80

1,00

1,20

AK Bellevue Prof Böhnke Dr Dörner Dr Kohm Prof Pasta Dr Sutter* Dr Gyori prof Zadok*

VA BINOCULAR 6 months follow-up

far inter near

MEAN UnCorected VA

(180 eyes)

FAR INTERMEDIATE

(65 cm)

NEAR

6 months

Follow-up

MONOCULAR 0.86 0.75 0.82

BINOCULAR 0.97 0.83 0.86

RESULTS**: 180 EYES

• *Prof Zadok: A const has been not optimized yet during his evaluation

• *Dr Sutter (5 pat.) : 1 patient – SEQ = -1.0; 1 patient astisgm. 1.75 dpt

* * Exact values of results might change by adding new patients results from other centres.

Comparison of Defocus curves Bi-Flex M and AT Lisa tri 839 MP (Zeiss)*

(binocular, follow-up 6M)

*P. Mojžíš, P. Peňa-Garcia, I. Liehneova, P. Žiak, J. Alio: Outcomes of a new diffractive

trifocal intraocular lens. J Cataract Refract Surg; 40:60-69, 2014

AT LISA Tri

Bi-Flex M – much better near VA, widen defocus curve for distance vision

(in agreement with PAD technology), competitive intermediate vision

(does not drop under 0.1 LogMar) to the trifocal IOL (Pasta J et al: presented at congress CSRKCH, CZ and at ESCRS London 2014)

Dunai A, Kranitzki K, Juhasz E, Nagy Z.

ESCRS 2016

Bi-Flex M contra ReStor (Alcon)

Bi-Flex M – 1 year follow up (binocular)

ESCRS 2016

Courtesy dr. Gyori, HU)

Contrast Sensitivity

• Photopic

• Mesopic

• In backlight

Courtesy by Dr Gyory, HU

Contrast Sensitivity:Comparison of Bi-Flex 677MY and FineVision

0

1

2

3

4

5

6

7

8

3 cpd 6 cpd 9 cpd 18 cpd

Photopic conditions

0

1

2

3

4

5

6

7

8

3 cpd 6 cpd 9 cpd 18 cpd

Mesopic conditions

0

1

2

3

4

5

6

7

8

3 cpd 6 cpd 9 cpd 18 cpd

Scotopic conditions

Bi-Flex 677 MY (AVG)

PhysIOL FineVision (AVG)

Bi-Flex 677 MY (AVG)

PhysIOL FineVision (AVG)

Bi-Flex 677 MY (AVG)

PhysIOL FineVision (AVG)

Courtesy by Dr Gyory, HU

VFQ 25 - page 1

Visual Functioning Questionnaire (VFQ) No problem Mild Moderate Strong Bad N/A

50 patients / Score 1 2 3 4 5 6 How much difficulty do you have with each of the following

Please tick the number from 1 to 6

Glare/Flare (trouble seeing street signs due to bright light or oncoming headlight? 27 20 2 - - -Night vision

49 1 - - - -Colour perception (trouble recognizing specific colours) 50 - - - - -Halos(rings around lights) 20 28 1 - - -Depth perception (trouble lining things up, pouring liquids or going down stairs) 50 - - - - -Distorted near vision

(straight lines looked crooked close up)50 - - - - -

Distorted distance vision (straight lines looked crooked at distance) 50 - - - - -

Blurred near vision49 1 - - - -

Blurred far vision50 - - - - -

Double vision49 1/? - - - -

Courtesy dr. Gyori, HU)

VFQ 25 - page 2Visual Functioning Questionnaire (VFQ) Response

1 to 6-point scale

VISUAL LIFESTYLE ACTIVITIES score 1 2 3 4 5 6

How much difficulty do you have with each activity due to your vision (without glasses or contact

lenses)

Watching TV or movies 48 2 - - - -

Playing or working outside 50 - - - - -

Caring for/playing with children 50 - - - - -

Reading the time on at alarm clock 48 2 - - - -

Seeing clearly when you wake up 46 4 - - - -

Reading the time on at wall clock 50 - - - - -

Performing your job/hobbies 48 2 - - - -

Participating in sports/recreation 50 - - - - -

Participating in social events 50 - - - - -

Reading and near work activities 48 2 - - - -

Driving at night 30 18 2 - - -

Driving when it is raining

Using a computer48

46

2

2

-

2

-

-

-

-

-

-

Cooking 50 - - - - -

Shopping 50 - - - - --

Using a cell phone 48 2 - - - --

Shaving or putting on make up 48 2 - - - -

50 patients

Courtesy dr. Gyori, HU)

Success of Progressive Bi-Flex M:

• Material - very low chromatic aberration

• Precision• PAD

• Apodisation• Special aberration on apodisative steps

increased depth of focus

• 1 DIFFRACTIVE ARRAY combined with PAD technology which does not sacrifices the “MTF peak” for far and near vision thanks to all technical properties and technical developments – progressive lens

• Clinical performance of Bi-Flex M supported by clinicalstudies is TRIFOCAL

References

• product websites

• www.gatinel.com

• Cionni, RJ et al: Get to Know the Defocus Curve, CRST, Nov 2010

• www.trioptics.com