Transcript Document

Comparison of the Optical Image
Quality for Presbyopia Correcting
IOLs using Modulation Transfer
Function Testing
W. Maxwell, MD, PhD
California Eye Institute
Fresno, California
Financial Disclosure: Consultant & Travel (Alcon Research, Ltd.)
W. A. Maxwell, MD, PhD
ASCRS 2008
Testing Methodology
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Study Objective
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Modulation Transfer Function (MTF) Testing
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To compare the image quality of various Presbyopia
Correcting IOLs with different designs (accommodative or
multifocal; aspheric or spherical) using the modulation transfer
function (MTF) testing method and U.S. Air Force 1951
Resolution Target (AFT) testing
Objective method of measuring image contrast degradation
at different spatial frequencies1
Modified ISO model eye
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The standard ISO Model Eye1 configuration incorporates a
35 mm doublet lens to converge light to simulate the
refractive power of a human cornea
The model cornea in the ISO Model Eye is an aberration free
lens, and is not representative of a typical human cornea
with its inherent positive spherical aberration
Thus, a modified ISO model eye, representing an average
human cornea, was used in this study
Ref 1: ISO 11979-2 Ophthalmic implants – Intraocular lenses – Part 2 Optical properties and test methods, 2000.
W. A. Maxwell, MD, PhD
ASCRS 2008
Optikos Video MTF measurement system
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1024 element detector, a 550 nm narrow band filter, and a 20X
microscope objective
IOLs were mounted in a lens holder under 10 mm of compression,
and aligned on the optical axis in a wet cell filled with deionized (DI)
water at 35 ± 2 °C with the anterior side of the IOL facing the
incident light
3 and 5 mm apertures used to simulate pupil size
Green light illuminates a single slit object located on the front focal
plane of a 180 mm collimator
The collimated light passes through the model cornea and IOL system
that simulates the vergence of a human eye
MTF Bench
IOL Models Tested
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ReSTOR SN6AD3 (Aspheric)
ReSTOR SA60D3 (Spherical)
Tecnis ZM900
Acri.Lisa 366D
ReZoom NXG1
Crystalens AT-50SE
IOL
Light
Source
CCD
Camera
Pinhole
Target
The optical bench setup
W. A. Maxwell, MD, PhD
ASCRS 2008
Modulation Transfer Function
5 mm Aperture, Distance Focus
Spatial Frequencies of 0 to 100 lp/mm
MTF %
100
90
ReSTOR Spherical SA60D3
ReSTOR Aspheric SN6AD3
Tecnis ZM900
Acri.Lisa 366D
ReZoom NXG1
Crystalens AT-50SE
Diffraction Limited
80
70
60
50
40
30
20
10
0
0
20
40
60
Frequency (lp/mm)
80
100
W. A. Maxwell, MD, PhD
ASCRS 2008
Modulation Transfer Function
5 mm Aperture, Distance Focus,
Discrete frequency of 100 lp/mm
25%
21%
MTF @ 100 lp/mm
20%
18%
14%
15%
12%
11%
10%
10%
5%
0%
ReSTOR
Aspheric
SN6AD3
Acri.Lisa
366D
Crystalens
AT-50SE
ReSTOR
Spherical
SA60D3
Tecnis
ZM900
ReZOOM
NXG1
W. A. Maxwell, MD, PhD
ASCRS 2008
Modulation Transfer Function
5 mm Aperture, Distance Focus,
Discrete frequency of 50 lp/mm
35%
30%
29%
MTF @ 50 lp/mm
25%
25%
24%
21%
20%
18%
16%
15%
10%
5%
0%
ReSTOR
Aspheric
SN6AD3
Acri.Lisa
366D
Crystalens
AT-50SE
ReSTOR
Spherical
SA60D3
Tecnis
ZM900
ReZOOM
NXG1
W. A. Maxwell, MD, PhD
ASCRS 2008
MTF of ReSTOR® & ReSTOR® Aspheric IOLs
3 mm Aperture
100
ReSTOR Spherical SA60D3
ReSTOR Aspheric SN6AD3
Tecnis ZM900
Acri.Lisa 366D
ReZoom NXG1
Crystalens AT-50SE
Diffraction Limited
90
80
MTF %
70
60
50
40
30
20
10
0
0
20
40
60
Spatial Frequency
80
100
W. A. Maxwell, MD, PhD
ASCRS 2008
Modulation Transfer Function
3 mm Aperture, Distance Focus,
Discrete frequency of 100 lp/mm
40%
MTF % @ 100 lp/mm
35%
33%
32%
31%
30%
30%
25%
20%
20%
15%
15%
10%
5%
0%
ReSTOR
Aspheric
SN6AD3
Acri.Lisa
366D
Crystalens
AT-50SE
ReSTOR
Spherical
SA60D3
Tecnis
ZM900
ReZOOM
NXG1
W. A. Maxwell, MD, PhD
ASCRS 2008
MTF % @ 50 lp/mm
Modulation Transfer Function
3 mm Aperture, Distance Focus,
Discrete frequency of 50 lp/mm
55%
50%
45%
40%
35%
30%
25%
20%
15%
10%
5%
0%
44%
47%
42%
41%
30%
22%
ReSTOR
Aspheric
SN6AD3
Acri.Lisa
366D
Crystalens
AT-50SE
ReSTOR
Spherical
SA60D3
Tecnis
ZM900
ReZOOM
NXG1
W. A. Maxwell, MD, PhD
ASCRS 2008
U.S. Air Force 1951 Resolution
Target Test (AFT)
U.S. Air Force 1951 Resolution Target Test (AFT)
 Optikos Optical Testing System as described for the
MTF test
 The setup for the AFT test was identical to that of
the MTF test, except the single slit object was
replaced with the AFT
 An image of the AFT was photographed through
each IOL
 The AFT test includes paired 3-bar target sets used
to qualitatively measure resolution efficiency
W. A. Maxwell, MD, PhD
ASCRS 2008
U.S. Air Force 1951 Resolution Target test
5 mm Aperture, Distance Focus
ReSTOR
Spherical
SA60D3
ReSTOR
Aspheric
SN6AD3
Tecnis
ZM900
ReZoom
NXG1
Acri.Lisa
366D
Crystalens
AT-50SE
W. A. Maxwell, MD, PhD
ASCRS 2008
Conclusions
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The AcrySof ReSTOR SN6AD3 aspheric IOL
produced the highest overall image quality for MTF
and AFT testing compared to several presbyopiacorrecting IOLs
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The Acri.Lisa IOL produced the second highest optical
quality, while the ReZoom IOL had the lowest optical
quality
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Clinical investigation is needed to determine whether
superior IOL optical quality demonstrated in optical
bench testing results in measurable visual
improvements in clinical practice
W. A. Maxwell, MD, PhD
ASCRS 2008