Iris color and age-related changes in lens optical density

Purpose: Epidemiologic evidence indicates that dark iris color increases ri sk of age-related cataract. No information is currently available, however, on the effects of iris color on the lens prior to cataract development In this study, we relate iris color to lens optical density (OD) in individual s without frank cataract. Methods: 90 subjects with blue or green irises (light color) were compared with 87 subjects having hazel, brown, or black irises (dark color). Lens OD was measured psychophysically by comparing scotopic thresholds obtained at 410 (measuring) and 550 nm (reference). Stimuli were presented in Maxwelli an view. Results: The groups with light and with dark iris color did not differ sign ificantly in smoking habits, dietary patterns, or age. Despite other simila rities between the groups, lens OD was significantly (p < 0.024) higher in the group with dark irises. The higher OD of the dark iris group was due to differences in the older subjects (>45 years, p < 0.005), rather than the younger subjects (20-45 years) who showed no differences in lens OD. Conclusion: Our data indicate that iris pigmentation may be directly relate d to age-associated increases in lens OD. (C) 2000 The College of Optometri sts. Published by Elsevier Science Ltd. All rights reserved.