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Study of the Alcon Restor +3

Add lens and the I‐ Diff Dr Cyres K. Mehta

Director‐International EyeCentres,

Mumbai



Diffrac:on

Movement

Imagine a wave of water striking a break in a dike.Asthe water passes throughthe dike, it spreads out onthe other side. That isDiffraction. Light acts in the

same way when it passesover a groove, or step, in alens.



Thomas Young's Diffraction ExperimentThomas Young's Diffraction Experiment

zero-orderaxial light (brighter)

1st-orderlight (dimmer)

Point LightSource

at Infinity

BendingBending &

Interference Pattern

Barrierwith Slits ScreenWave Crest



Diffrac:ve Interac:on

Light

entersthis side

Light is diffractedthrough apertures

As the waves spreadout and bump into

each other,constructive anddestructiveinterference occurs.

1.

2.



MONOFOCAL LENS

PARALLEL RAYS ARE COMBINED BY A LENS INTO ONEFOCUS



DIFFRACTION THROUGH A PLANE LENS

THE DIFFRACTION EFFECT IS CAUSED BY A MICRO STRUCTUREDSURFACE PROFILE OF THE LENS

THE SIZE OF THE STRUCTURES IS IN THE ORDER OF MICRONS.

A DIFFRACTIVE LENS COMBINES PARALLEL RAYS ALSO TO A FOCUS, BUTTHE OPTICAL PATH LENGTH OF EACH RAY DIFFERS FROM ZONE TO ZONEBY ONE WAVELENGTH.



Diffractive bifocal lens

Refractive lens + diffractive microstructure

Beamsplitting by energy division (physical beamsplitter)

Advantages: The brightness distribution is independent of the pupil size.The visual acuity is not limited by diffraction effects at thezones.



Diffractive bifocal lens

Because of a saw tooth shape of the surface profile with adepth smaller than one wavelength, diffraction causes a bifocaleffect.

The diffracted light contributes to the near focus and theundiffracted light to far focus.

The brightness ratio of far and near focus can be tuned by theprofile depth.

λ



Physics ‐ Bifocal IOL



Surface profile

Interferometric measurement of the surface profile



iDIFF Presbyopic IOL

• Refractive-Diffractive

Technology

• Addresses Cataract

Patients with or withoutPresbyopia

* Allowed Patients a High

Level of Freedom From

Glasses in clinical trial



iDIFF Features based on Benefits



Smooth Transi:on Zones



Full Optic Diffractive IOL

Advantages

Provides multifocal vision

Reduced pupil dependency

Balanced distribution of light

energy for all pupils

Less sensitive for decentration

* Creates Halos and scattering Light

Disadvantages

Potential for glare and halos at

night



advantages

Provides multifocal vision

Reduced pupil dependency

Balanced distribution of light energyfor all pupils

Less sensitive for decentration

Reduces halos through perfect

distance distribution of light

Reduced straight through smooth steps

iDIFF IOL

iDIFF Design Advantages



Perfect Light Distribu:on forDistance &Near( 60/40)



Works Independent of Pupil Size



Aspheric Op:c



Spherical Aberra:on is s:ll

increased

Aer IOL Implanta:on?



Aspheric Op6c

of the IOL

Spherical Aberra:on is

eliminated



ASPHERIC PLATFORM IS BETTER FOR MULTIFOCALS-MTF of a spherical monofocal and an aspherical IOL

ideal monofocalvision (diffractionlimited)

MTF spherical PMMA IOL MTF aspherical Silicone IOL

Normalized spatial frequencyUniversität Karlsruhe, ITIV

Normalized spatial frequencyUniversität Karlsruhe, ITIV

loss of contrast vision dueto spherical aberration

ideal contrast vision, nospherical aberration



• Edge thickness correspond to

standard designed IOLs

• Square edge design

• Extremely low incidence of PCO

• An: Z effect Hap:c design

iDIFF 360⁰square Edge



+3.5 Addi:on for Near Vision



AcrySof ® ReSTOR® Aspheric IOL

SN6AD3 Add Power: +4 DSpectacle Plane: 3.2 DRange: +10 D to +34 D

A‐Constant: 118.9

SN6AD1 Add Power: +3 DSpectacle Plane: 2.4 DRange: +10 D to +34 D

A‐Constant: 118.9



Discussion Topics Aspheric (SN6AD3) vs. Spheric (SN60D3)

Introduction of SN6AD1

True performance at near, intermediate, and distance Comparison between SN6AD1 and SN6AD3

High resolution image quality

Minimal visual disturbances



AcrySof® ReSTOR®

Aspheric IOL



Anatomy of the Apodized Diffrac:ve

Technology

A +4 D at lens plane

equaling +3.2 atspectacle plane

Central 3.6 mmapodized diffractivestructure

Step heights decrease

peripherally from1.3 – 0.2 microns

Anterior asphericoptic

Outer refractivezone



Anterior AsphericOptic

Anterior ApodizedDiffractiveOptic

Symmetric Biconvex

13.0 mm

6.0 mm 6.0 mm

Anatomy of the Apodized Diffrac:ve

Technology



Apodiza6on

Gradual reduction or blending of the diffractive step heights.

Optimally manages light energy delivered to the retina as itdistributes the appropriateamount of light to near anddistant focal points, regardless of the lighting situation.

Designed to improve imagequality while minimizing visualdisturbances.

1.3 micronstep



Technology of the AcrySof ® ReSTOR® IOL in

“human” terms

Thickness of a Human Hair = 60microns

Thickness of a Red Blood Cell = 7microns

Step Height at periphery of thediffractive portion of the AcrySof®ReSTOR® Aspheric IOL = 0.2 microns



Design Objec:ve

Design considerations for the AcrySof® ReSTOR® Aspheric IOL:

Induce negative Spherical Aberrations with the lens to

compensate for positive corneal Spherical Aberrations

Source: SN6AD3 Package Insert



Assessing IOL performance

Modula:on Transfer Func:on (MTF)

The MTF describes the loss in contrast in the image of asinusoidal pattern. The MTF depends upon spatial frequency.

Lens

0

0.25

0.50

0.75

1.00

0 100 200 300 400

M T F C o n t r a s t

Spatial Frequency (lp/mm)

The MTFPointobject

Pointimageis spreadout

Image contrast, and MTF,decrease as the “spatialfrequency” increases,even for a perfect lens

A i IOL f



Assessing IOL performance

Light Spreading at Circular Apertures

Clear aperture(Airy Pattern)

0.5 radiusobstruction(or redirectionto other focus)

0.8 radiusobstruction(or redirectionto other focus)

MTF (Image Contrast)

0

0.25

0.50

0.75

1.00

0 100 200 300 400



0

0.25

0.50

0.75

1.00

0 100 200 300 400



0

0.3

0.5

0.8

1.0

0 100 200 300 400



focusing regionof lens aperture

Point image

6/6 or 20/20

vision

6/6 or 20/20vision

6/6 or 20/20vision



Summary Op:cal Quality Comparison

Alcon ReStor®

Precision MTF

AMO ReZoom

Full Optic Blur

AMO Tecnis

Central Optic Blur

Dr Ligabue



Summary Night Vision Comparison

ReSTOR

Best Image

Tecnis MF

Poor Resolution

ReZoom

Worst Resolution



SN6AD1 Design Characteris:cs Utilizes existing ReSTOR® Aspheric +4 D platform

with identical asphericity, energy distribution profile,and shape factor

Modified add power from +4 D to +3 D 9 diffractive rings vs. 12 diffractive rings

Slightly wider ring spacing to modify the add power



Both +4 D and +3 D have 3.6 mm Apodized Diffractiveregion

+4 D central zone diameter = 0.742 mm

+3 D central zone diameter = 0.856 mm

+4 D, 12 zones

+3 D, 9 zones

Physical Comparison



Study Objec:ve To confirm that the increase in the distance of near vision for the ReSTOR ® Aspheric +3 D IOL does notnegatively impact:

visual acuity at near, distance, or intermediate contrast sensitivity

halo visual disturbance scores

as compared to the ReSTOR ® Aspheric +4 D IOL



Study Design



True VA Performance

Near Intermediate Distance



Mean Distance VA

-0.10

0.30

Uncorrected VA Best Corrected VA

L o g M A

R

ReSTOR® Aspheric +3 D N=138 ReSTOR® Aspheric +4 D N=1313 Year (N=7)

20/20

20/25

Both VAs are less than one letter different

20/32

20/40

Data on File. Alcon, Inc.



Mean Near VA at Best Distance

-0.10

0.30

Uncorrected VA Distance Corrected VA

L o g M A

R


20/20

20/25

Both VAs are less than 2 letters and both 20/25

20/40

20/32




Mean Distance of Best Near VA

28.00

30.75

33.50

36.25

39.00

Uncorrected in cm Distance corrected in cm

ReSTOR® Aspheric +3 D N=138

ReSTOR® Aspheric +4 D N=131North

ReSTOR® Aspheric +3 D has approximately 6.5 cm (2.6 in)increase in distance compared to ReSTOR® Aspheric +4 D

D i s t a n

c e i n c m




Mean Uncorrected Intermediate VA

VAs are approximately 1-1.5 line(s) better for ReSTOR®

Aspheric +3 D

0

0.40

50 cm 60 cm 70 cm

L o g M

A R


20/20

20/25

20/32

20/40




Mean Distance Corrected Intermediate VA

0

0.40

50 cm 60 cm 70 cm

L o g

M A R


20/25

20/32

VAs are approximately 1.5 lines better for ReSTOR®

Aspheric +3 D

20/20

20/40


bi d ’



Combined VA’s

Distance, Intermediate, Near

0

20.0000

40.0000

60.0000

80.0000

100.0000

20/20 or better 20/25 or better 20/32 or better 20/40 or better worse than 20/40

P

e r c e n t o f S u b j e c t s





Bilateral Defocus Curve

20/20

20/40

-0.15

0

0.15

0.30

0.45

0.60

2 1.5 1 0.5 0 0.5 -1 -1.5 -2 -2.5 -3 -3.5 -4 -4.5 -5

ReSTOR® Aspheric +3 D ReSTOR® Aspheric +4 D

l o g M A R

Refraction (D)




Mean Visual DisturbancesProblems with Night Vision

Problems with Color Perception

Halos

Glare/Flare

Double Vision

Distorted Near Vision

Distorted Far Vision

Blurred Near Vision

Blurred Far Vision

0 1.8 3.5 5.3 7.0

Bar 3 ReSTOR® Aspheric +4 D N=131 ReSTOR® Aspheric +3 D N=138

Mild Moderate SevereNone


Frequency of Spectacle Wear (Distance



Frequency of Spectacle Wear (Distance

Vision)

0 %

25 %

50 %

75 %

100 %

Never Sometimes Always

ReSTOR® Aspheric +3 D N=138ReSTOR® Aspheric +4 D N=131North

How often do you wear glasses?Data on File. Alcon, Inc.



Frequency of Spectacle Wear

0 %

25 %

50 %

75 %

100 %

Never Sometimes Always



North

How often do you wear glasses?Data on File. Alcon, Inc.

96% f R STOR 3 P : t W ld H th



96% of ReSTOR +3 Pa:ents Would Have the

Same Implant Again

0 %

25 %

50 %

75 %

100 %

No Yes

ReSTOR® Aspheric +3 D N=149ReSTOR® Aspheric +4 D N=139North

Would you have the same implant again?

P e r

c e n t o f S u b j e c t s




AcrySof® ReSTOR® Aspheric IOL

Conclusions• True performance at near, intermediate, and distance

• ReSTOR® Aspheric +3 D IOL provides a range of near vision• Best distance approximately 7cm out for ReSTOR® Aspheric +3 D IOL

• 1 – 1.5 line(s) improvement in intermediate VA

• Aspheric optic provides improved image quality

• No significant differences in visual disturbances

• High rate of patient satisfaction and spectacle independence



So,to summarise Today we can offer refractive cataract surgery to our

clients at different price points with diffractive lenses

New technologies ensure good near vision,minimalglare and haloes and even decent intermediate vision.



SEE YOU AT PRESBYMANIA 2010

apodized model alcon

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