Long-term exposure to solar ultraviolet radiation as a risk factor for age-related macular degeneration

A clinical epidemiological study has been conducted as apart of research project investigating chronic exposure to solar ultraviolet radiation (UVR) as a factor contributing to the onset of age-related macular degeneration (ARMD). The study included 623 subjects older than 50 from two different geographic areas, one with high solar radiation (the island of Solta - Region 1) and the other (Zagreb and its surroundings - Region 2) with low solar radiation. Individual exposure to UVR was assessed according to global exposure to sunlight, on the basis detailed history of life-long exposure to sunlight, with special reference to professional history and geophysical specificities of the respective areas. Different grades of ARMD were based on the fundus photographs and flourescein angiography. Statistically significant relation was found between ARMD and mean daily exposure (in hours) to solar radiation in Region 1 (chi2 = 186.22; p = 0.000), Region 2 (chi2 = 25.66; p = 0.000) and in both regions together (chi2 = 216.43; p = 0.000). ARMD is more frequent in the subjects belonging to the Region 1 and with the same exposure to sunlight (8 hours and more) which goes in favor of their increased UVR exposure. The results support a relationship between long-term sunlight exposure and increased risk of ARMD.