Light exposure and the risk of cortical, nuclear, and posterior subcapsular cataracts: the Pathologies Oculaires Liées à l'Age (POLA) study.

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.