Light scattering and light transmittance in intraocular lenses explanted because of optic opacification

Abstract

Purpose: To assess light scattering and light transmittance in intraocular lenses (IOLs) explanted because of optic opacification.

Setting: John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA.

Design: Experimental study.

Methods: Poly(methyl methacrylate) (PMMA) IOLs with snowflake degeneration, hydrophilic acrylic IOLs with different calcification patterns, and 1 calcified silicone IOL explanted from an eye with asteroid hyalosis were studied with gross and light microscopy. Light scattering was measured with an EAS-1000 Scheimpflug camera. Light transmittance was measured with a Lambda 35 UV/Vis spectrophotometer (single-beam configuration with RSA-PE-20 integrating sphere). Analyses were performed at room temperature in the hydrated state and compared with controls.

Results: The study evaluated 8 PMMA IOLs, 22 hydrophilic acrylic IOLs, and 1 silicone IOL. Light scattering was as follows: 208 to 223 computer-compatible tapes (CCTs) for PMMA IOLs with snowflake degeneration (control = 9 CCTs); 90 to 227 CCTs for calcified hydrophilic acrylic IOLs (controls = 12 to 23 CCTs); 223 CCTs for the calcified silicone IOL (control = 5 CCTs). The mean light transmittance in the visible light spectrum was 81.08% to 97.10% for PMMA IOLs (control = 98.80%); 78.94% to 97.32% for hydrophilic acrylic IOLs (controls = 97.32% to 98.66%); 94.68% for the silicone IOL (control = 97.74%).

Conclusion: Intraocular lens opacification led to very high levels of light scattering and a potential for decreased light transmittance, which play a role in the development of symptoms such as glare and halos, decreased contrast sensitivity, and eventually decreased visual acuity.

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