Light exposure and the risk of cortical, nuclear, and posterior subcapsular cataracts - The Pathologies Oculaires Liees a l'Age (POLA) study

Background: Exposure to light may be an important risk factor for the devel opment of cataracts. Objective: To present the relation of ambient solar radiation and professio nal and leisure exposures to light with the different types of cataracts. Methods: Pathologies Oculaires Liees a l'Age (POLA) is a population-based s tudy on cataract and age-related macular degeneration and their risk factor s in 2584 residents of Sete (southern France). Cataract classification was based on lens examination at slitlamp according to Lens Opacities Classific ation 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 [Cr], 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 c ortical and mixed cataract and cataract surgery, respectively. Solar ambien t radiation was not significantly associated with posterior subcapsular and nuclear cataracts. By contrast, posterior subcapsular cataracts were signi ficantly 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.