Optical performance of hydrophobic acrylic intraocular lenses with surface light scattering.

Purpose: To evaluate the potential effect of surface light scattering on the optical performance of hydrophobic acrylic intraocular lenses (IOLs) made of Acrysof material.

Setting: Alcon Laboratories, Inc., Fort Worth, Texas, USA.

Design: Experimental study.

Methods: Explanted IOLs from cadaver eyes with more than 50 computer-compatible tape (CCT) units of scatter were selected, yielding 7 IOLs. Clinically explanted IOLs (n = 4) were obtained after IOLs had been implanted 8.5 to 10.5 years. Explanted IOLs were matched to unused control IOLs. After proteins were removed, scatter was measured for IOLs dry, wetted (2 minutes in a balanced salt solution), and hydrated (24 hours). Badal imaging, ultraviolet-visible transmission, and modulation transfer function (MTF) measurements were performed with hydrated IOLs.

Results: Hydrated scatter values ranged from 80 to 221 CCT for explanted IOLs and 2 to 7 CCT for controls. No differences in Badal image resolution were observed between explanted IOLs and controls. The mean MTF values at 100 line pairs per mm (representing 20/20 visual acuity) were similar between explanted IOLs and controls. Over the range of 400 to 700 nm, a small reduction (mean 2.1% ± 1.4% [SD]) in transmission was observed.

Conclusions: Surface light scattering of explanted IOLs did not affect image resolution or MTF values. Although light transmission was slightly decreased, the magnitude appeared to be inconsequential for optical performance.