The Effect of Hypotensive drugs on Intraocular Lens Clarity

Abstract

Purpose : To assess the effect of hypotensive drugs on light absorbance, discoloration, opacification and precipitate formation of IOLs

Methods : In this laboratory study, four types of IOLs (hydrophilic and hydrophobic acrylic) were soaked in solutions containing Brimonidine-tartrate 0.2%, Brimonidine-tartrate/Timolol-maleate 0.2%/0.5%, Dorzolamide 2%, Dorzolamide/Timolol-maleate 2%/0.5%, Latanoprost 0.005% and Timolol-maleate 0.5%. Non-treated IOLs and IOLs soaked in Balanced Salt Solution (BSS) served as controls. All Treated lenses were sealed in glass containers and placed in an oven at 82 degrees Celsius for 120 days (approximating 10 years in 37 degrees according to The Arrhenius equation).
Each IOL underwent four examinations: gross inspection by light microscopy, light absorbance by a photo-spectrometer, Scanning Electron microscopy and an Energy-dispersive X-Ray spectrometry.

Results : A total of 98 acrylic IOLs of 4 different models, were included in the study. 49 hydrophilic and 49 hydrophobic. All BSS-soaked IOLs appeared clear with no significant discoloration or precipitates formation and light absorbance in these lenses was comparable to that of non-soaked, non-heated IOLs (P>0.05).
Gross examination revealed brown discoloration of IOLs Soaked in solutions containing Dorzolamide and a yellow discoloration of IOLs soaked in solutions containing Brimonidine. Precipitates of different size, morphology and distribution were seen on hydrophilic and hydrophobic IOLs soaked in solutions containing Latanoprost, Timolol and Brimonidine. Opacification was noted in both hydrophilic and hydrophobic IOLs. Glistening was formed in one IOL model soaks in 6 different solutions, including BSS.
Significant difference in light absorbance was documented between IOLs soaked in Brimonidine/Timolol, Dorzolamide, Dorzolamide/Timolol and latanoprost as compared to control (P<0.03).
In most areas of precipitated, spectrometric signatures of Calcium and phosphor was obtained. Brown discolored IOLs contained sulfur.

Conclusions : Interactions between different hypotensive drugs and different IOLs exist in manner of change in light absorbance, discoloration and precipitate formation in-vitro

This is a 2021 ARVO Annual Meeting abstract.

 

An overview of the variety of findings in this study: discoloration, opacification, precipitates formation and glistening of different IOL types soaked in different hypotensve drugs.