Ocular exposure to sunlight and risk of lens opacities in a population based study of older americans: The see study

Purpose: The purpose of this population-based study was to determine the association of sunlight exposure, particularly UV-B exposure, and risk of opacities, in the population and among gender and racial groups, using carefully constructed models of ocular exposure. Methods: For each individual, the ocular dose of UV-B was derived using our model which combines ambient data, field studies on ocular/ ambient exposure, history of time outside, glasses and hat use. Photographs of the lenses were taken, and graded using the Wilmer Grading Scheme for the presence and severity of nuclear, cortical, and PSC opacities. Data on other risk factors were obtained by interview on the 2520 participants in the SEE project. Results: The median of average annual ocular exposure to UV-B in this population was estimated at .009 Maryland Sun Years (MSY), with a maximum of 09. Women had lower exposures compared to men. African Americans had similar median exposures compared to whites, but upper quartile exposures tended to be higher. The risk of cortical opacities in white and African American men increased with increased levels of exposures; among women the association was not marked, and increased only in the higher quartiles of exposure. Adjusting for other factors, average annual UV-B exposure was significantly related to risk of cortical opacities in this population (OR= 1.10 for each increase in .01 MSY, 95% CL=1.02-1.19). Conclusions: Even within the low doses of ocular exposure to UV-B encountered in the general population, there appears to be an association with risk of cortical opacities.