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

Abstract

To assess light scattering and light transmittance in intraocular lenses (IOLs) explanted because of optic opacification. John A. Moran Eye Center, University of Utah, Salt Lake City, Utah, USA. Experimental study. 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 35UV/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. 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%). 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. No author has a financial or proprietary interest in any material or method mentioned.