This document discusses the development of new test methods for evaluating intraocular lens (IOL) designs. Over 3 million IOL implants are performed annually in the US. New IOL designs have introduced complications requiring standardized test methods. The authors describe a confocal laser method to objectively measure different IOL designs, materials, and properties like focal length and scattering. Laser stability is necessary for quantitative measurements. The method allows for improved vision outcomes and quality testing of new IOL designs.

1. Intraocular lens (IOL) implantation in
refractive cataract surgery is the most
commonly performed surgery (more than 3
million IOLs implanted in USA per year)
New IOL designs have introduced new
complications that can result in visually
impaired patients
Quantitative standard test methods required
to minimize possible aversive effects from
IOL implants
Development of Innovative Test Methods for Laboratory Evaluation of Critical Optical
Properties of Novel Intraocular Lens (IOL) Designs
Aurin Chakravarty1, Bennett N. Walker1, Robert H. James1, Don Calogero2,
and Ilko K. Ilev1
1OTMN Lab/DP/OSELCDRH; 2DONED/ODE/CDRH; FDA, Silver Spring, MD
FDA/CDRH Critical Path Poster Session; August 1, 2012
BACKGROUND
CONFOCAL LASER METHOD
RESULTS
STABILITY
Precise quantitative method to
objectively measure IOLs
with different designs,
materials, etc.
Improved quality of vision for
thousands of patients
PM
LASER
IOLOC
Oin
MULTIFOCAL LENS
CHARACTERIZATION
0:10 0:20 0:30 0:40 0:50
0.072
0.076
0.080
0.084
0.088
0.092
Power(W)
Time(Min)
0:10 0:20 0:30 0:40 0:50
0.052
0.056
0.060
0.064
0.068
Power(W)
Time(Min)
FOCAL LENGTH
DETERMINATION
Laser stability is
necessary to make
quantitative readings
DISCUSSION
Stability of 543
nm laser
Stability of 658
nm laser
Ilev, EYE, v.21, p. 818, 2007, Nature
Ilev, Patent No. 7,719,668; May 18th, 2010
Multifocal lens scattering
Multifocal Lens
75x
Multifocal Lens
150x
Theoretical D: 25 diopters
Actual D: 24.4 diopters
Expected error due to the
following parameters: water,
glass cuvet, etc.
-20000-15000-10000 -5000 0 5000
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
-19250 -19200
0.138
0.140
0.142
0.144
0.146
Power(mW)
Distance (m)
Power(mW)
Distance (m)
Mirror
position 1
IOL Mirror
position 2
F/2
Focal length
-2000 0 2000
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
Power(mW)
Distance (m)
1: 1062 µm
2: 386 µm
1
2
OC IOL
Scattering setup
Scattering
image
D ≈ d: Quantitative analysis
with multifocal lenses is
achievable
D= 1062 µm
d= 711 µm (from FWHM)