Effect of Ultraviolet Radiation on Cataract Formation

TLDR

The study examined the association between ultraviolet radiation and cataract formation in 838 Chesapeake Bay watermen. Cumulative UV exposure was estimated from age 16 using detailed occupational histories and laboratory/field measurements, and cataracts were graded by ophthalmologic examination for type and severity. High cumulative UVB exposure was associated with a significantly increased risk of cortical cataract—doubling exposure raised risk by 1.6 times, and those in the upper quartile had a 3.3‑fold higher risk—while no link was found with nuclear cataracts or UVA exposure, supporting the need for UVB ocular protection.

Abstract

To investigate the relation of ultraviolet radiation and cataract formation, we undertook an epidemiologc survey of 838 watermen (mean age, 53 years) who worked on Chesapeake Bay. The annual ocular exposure was calculated from the age of 16 for each waterman by combining a detailed occupational history with laboratory and field measurements of sun exposure. Cataracts were graded by ophthalmologic examination for both type and severity. Some degree of cortical cataract was found in 111 of the watermen (13 percent), and some degree of nuclear cataract in 229 (27 percent). Logistic regression analysis showed that high cumulative levels of ultraviolet B exposure significantly increased the risk of cortical cataract (regression coefficient, 0.70; P = 0.04). A doubling of cumulative exposure increased the risk of cortical cataract by a factor of 1.60 (95 percent confidence interval, 1.01 to 2.64). Those whose annual average exposure was in the upper quartile had a risk increased by 3.30 (confidence interval, 0.90 to 9.97) as compared with those in the lowest quartile. Analysis using a serially additive expected-dose model showed that watermen with cortical lens opacities had a 21 percent higher average annual exposure to ultraviolet B (t-test, 2.23; P = 0.03). No association was found between nuclear cataracts and ultraviolet B exposure or between cataracts and ultraviolet A exposure. We conclude that there is an association between exposure to ultraviolet B radiation and cataract formation, which supports the need for ocular protection from ultraviolet B. (N Engl J Med 1988; 319:1429–33.)