Variations in refractive analysis with different diffractive multifocal intraocular lenses using different wavefront analyzers

Mami Yoshino, Hiroko Bissen-Miyajima, Shinichi Oki,

Keiichiro Minami, Kunihiko Nakamura Department of Ophthalmology

Tokyo Dental College Suidobashi Hospital, Tokyo, JapanNaoyuki Maeda

Department of Ophthalmology Osaka University Medical School, Osaka, JapanYoshino, Bissen-Miyajima, Oki, Minami and

Nakamura: No financial InterestMaeda: Research grant recipient from Topcon Corp.

PURPOSE

It is still under discussion whether the Hartman-Shack wavefront analyzer represents real wavefront aberration of the multifocal intraocular lens (MF-IOL) implanted eye. This study evaluated the refractions of diffractive MF-IOL implanted eyes using two wavefront analyzers with manifest refraction.

SUBJECTS 15 eyes of 8 patients who received diffractive MF-IOL

METHODS

Manifest Refraction

Refraction by wavefront analyzer1. KR-9000PW (Topcon, Japan)2. WaveScan (AMO, US)

VS: 0.9 (1.2 x +0.75D sph. cyl. -0.75 D)

Spherical refraction

Cylindrical refraction

To verify if the wavefront analyzer results represent real wavefront aberration, refraction data were compared with those with manifest

Wavefront Analyzer

KR-9000PW WaveScan

Wavefront sensor Hartmann-Shack Hartmann-ShackNo of spots (7 mm pupil)

169 points 240 points

Wavelength at measure

840 nm 785 nm

Centering point Corneal apex Pupil center (scotopic)

Examination room Room light Dim light (5cd/m2 )Pupil Dilated ScotopicRefraction Spectacle plane Spectacle plane

Optical zone: 4 mm & 6 mm

WaveScan

Optical zone: 5.94±0.75 mm

Hartmann-Shack spot images and evaluation

ZM900 SA60D3

Spots were doubled

Spots were clearer in the

center

ZM900 SA60D3

Analysis difficult due to spot irregularity

Spots were doubled

or not clear

Evaluation was possible in all eyes tested

3 eyes failed for evaluation

KR-9000PW

Manifest Wavefront Difference

p value (Wilcoxon)

Sphere (D)Total 0.27±0.52 0.52±0.49 0.25±0.3

0p<0.05

ZM900 0.17±0.33 0.57±0.25 0.40±0.13

p<0.01

SA60D3 0.42±0.74 0.45±0.75 0.04±0.36

p=0.917

Cylinder (D)

Total -0.62±0.43 -0.98±0.45 0.36±0.38

p<0.01

ZM900 -0.47±0.46 -0.70±0.31 0.22±0.32

p=0.086

SA60D3 -0.83±0.30 -1.10±0.69 0.58±0.40

p<0.05

RESULTS ：　KR-9000PW

Manifest Wavefront Difference P value (Wilcoxon)

Sphere (D)Total 0.27±0.5

21.04±0.51 0.71±0.56 p<0.05

ZM900 0.17±0.33

1.07±0.50 0.88±0.41 p<0.05

SA60D3 0.42±0.53

0.98±0.53 0.34±0.62 p=0.273

Cylinder (D)Total 0.62±0.4

3-

0.94±0.600.32±0.41 p<0.01

ZM900 0.47±0.46

-0.69±0.37

0.16±0.29 p<0.05

SA60D3 0.83±0.30

-1.45±0.36

0.64±0.52 p=0.144

RESULTS ：　WaveScan

The difference of spherical and cylindrical refractions between manifest and wavefront were within 0.5D.

Coincidence in refraction may support that Hartmann-Shack analyzer measures distance wavefront of diffractive MF-IOL properly.

DISCUSSION ：　 Reliability of refraction with Hartmann-Shack analyzer

Cyrindrical refraction was very close between KR-9000PW and WaveScan.

With KR-9000PW, spherical refraction was closer to manifest.

DISCUSSION ：Differences between 2 wavefront analyzers

Differences between 2 multifocal IOLs Hartmann-Shack images were clearer and easier

to be analyzed in eyes with ZM900.

CONCLUSION In this preliminary study, the difference

between the wavefront refraction and manifest refraction can be influenced by the design of the diffractive MF-IOL and the characteristics of the wavefront analyzer.

These effects should be considered for not only 2nd order aberration, but also higher order aberration in eyes with diffractive MF-IOLs.

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