A review of the epidemiologic evidence linking ultraviolet radiation and cataracts.

BACKGROUND/AIMS: Cataract is the most common cause of blindness in the world and there are currently no strategies to prevent it. The aim of this paper is to review the epidemiologic evidence linking ultraviolet (UV) radiation and cataract. METHODS: Published epidemiologic research articles on UV and cataract were reviewed against the epidemiologic criteria for causality: biological plausibility, strength of the association, specificity, experimental evidence, temporal sequence of events, dose-response relationship, and consistency. RESULTS: The majority of the 22 epidemiologic studies reviewed met most of the epidemiologic criteria for causality and support an association between UV-B and the development of cortical cataract and perhaps posterior subcapsular cataract. CONCLUSIONS: The epidemiologic data justify the implementation of public health campaigns to raise public awareness of the risk of cortical cataract due to ocular UV-B exposure. Future researchers should be careful to avoid potential bias by measuring personal ocular UV exposure and by quantifying cataract carefully.