Light Exposure and the Risk of Cortical, Nuclear, and Posterior Subcapsular Cataracts

BACKGROUND: Exposure to light may be an important risk factor for the development of cataracts. OBJECTIVE: To present the relation of ambient solar radiation and professional and leisure exposures to light with the different types of cataracts. METHODS: Pathologies Oculaires Liées a l'Age (POLA) is a population-based study on cataract and age-related macular degeneration and their risk factors in 2584 residents of Sète (southern France). Cataract classification was based on lens examination at slitlamp according to Lens Opacities Classification System III. A questionnaire about light exposure was administered. RESULTS: After multivariate adjustment, participants who had higher ambient solar radiation had a 2.5-fold (95% confidence interval CI, 1.2-5.0), 4.0-fold (95% CI, 2.0-8.0), and 2.9-fold (95% CI, 1.5-5.3) increased risk of cortical and mixed cataract and cataract surgery, respectively. Solar ambient radiation was not significantly associated with posterior subcapsular and nuclear cataracts. By contrast, posterior subcapsular cataracts were significantly associated with professional exposure to sunlight (odds ratio OR, 1.63; 95% CI, 1.01-2.63) and frequent use of sunglasses (OR, 0.62; 95% CI, 0.43-0.90). Mixed cataract was also associated with professional exposure to artificial light (OR, 3.02; 95% CI, 1.03-8.82). CONCLUSION: Our study further confirms the role of sunlight exposure in the pathogenesis of cataract, in particular in its cortical localization.