Objective evaluation of through-focus optical performance of presbyopia-correcting intraocular lenses using an optical bench system

Abstract

Purpose: TO evaluate spherical aberration and through-focus optical performances of 5 presbyopia-correcting and 2 monofocal intraocular lenses (IOLs).

Setting: Flaum Eye Institute, University of Rochester, Rochester, New York, USA.

Design: Experimental study.

Methods: Five presbyopia-correcting IOLs (Restor +4D SN6AD3, Restor +3D SN6AD1, Rezoom NXG1, Tecnis multifocal ZM900, Crystalens HD500) were tested using an optical bench system consisting of a model eye, a high-resolution Hartmann-Shack wavefront sensor, and an image-capturing device. Two monofocal IOLs (Sofport AO LI60AOV, Acrysof SN60AT) were measured for comparison. No accommodation was simulated. The spherical aberration profiles of each IOL were measured using the wavefront sensor. Through-focus performance was evaluated by calculating cross-correlation coefficients and comparing the likenesses of captured images of a resolution target and a perfect reference image.

Results: With a 5.0 mm entrance pupil, the SN6AD3, SN6AD1, ZM900, NXG1, and HD500 IOLs had spherical aberration of -0.18 μm, -0.14 μm, -0.15 μm, -0.07 μm, and -0.01 μm, respectively. Distance image quality was poorer with multifocal and accommodating IOLs than with monofocal IOLs. All multifocal IOLs had effective distance and near image quality but had a loss in intermediate image quality. The HD 500 accommodating IOL had decreased distance image quality and slightly increased depth of focus compared with the monofocal IOLs because of the bispheric design.

Conclusions: The presbyopia-correcting IOLs had different optical characteristics, including spherical aberration profile and through-focus performance. An accurate understanding of the optical characteristics of individual IOLs is essential to selecting the best presbyopia-correcting IOL and thus improving cataract surgery outcomes.

Financial disclosure: No author has a financial or proprietary interest in any material or method mentioned.

Copyright © 2011 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Figures

Figure 1

A: Diagram of an optical bench (FL: fiber laser, AFRT: air force resolution target, L1: lens 1, L2: lens 2, L3: lens 3, AP: artificial pupil, PC: pupil camera, AT: alignment target, TL: trial lens, WC: wet cell, IOL: intraocular lens, WS: wavefront sensor, IS: image sensor). B: Cropped image of a 1951 United States Air Force resolution target.

Figure 1

A: Diagram of an optical bench (FL: fiber laser, AFRT: air force resolution target, L1: lens 1, L2: lens 2, L3: lens 3, AP: artificial pupil, PC: pupil camera, AT: alignment target, TL: trial lens, WC: wet cell, IOL: intraocular lens, WS: wavefront sensor, IS: image sensor). B: Cropped image of a 1951 United States Air Force resolution target.

Figure 2

Change in primary spherical aberration as a function of pupil size.

Figure 2

Change in primary spherical aberration as a function of pupil size.

Figure 3

Through-focus images for a 3 mm pupil.

Figure 4

Cross-correlation coefficients for a 3 mm pupil.