Sunlight, skin sensitivity, and senile cataract

This study explores the association between sunlight exposure and senile cataract, taking into account such individual differences as skin sensitivity to sunlight and the use of sun-shielding devices, i.e., sunglasses and hats. A case-control study was conducted among 160 matched pairs of subjects between October 1, 1984 and June 1, 1985 at the University of Iowa Hospitals and Clinics in Iowa City, Iowa. Cases were selected from among all patients admitted for inpatient or outpatient cataract surgery who were at least 40 years old. Controls were selected from among those waiting for a friend or relative who was attending one of the ophthalmology clinics. Controls were matched to the cases on a 1:1 basis on sex and age (+/- one year). No association was observed between history of sunlight exposure and senile cataract. However, independent of sunlight exposure, the cases with nuclear cataracts reported a more severe acute skin response upon exposure to sunlight for the first time in the summer (a severe burn with blistering) than did their age- and sex-matched controls (McNemar odds ratio (OR) = 1.73, 95% confidence interval (CI): 1.03-2.91). In addition, independent of sunlight exposure, the male controls reported a greater average lifetime use of head coverings in summer which shaded their eyes from the sun than did their age- and sex-matched cases (McNemar OR = 0.48, 95% CI: 0.25-0.94).