PURPOSE: To investigate the effect of age on ultraviolet radiation-B (UVR-B)-induced cataract and to detect the maximum acceptable dose in rats of different age groups. METHODS: Four age groups of 20 rats each, aged 3, 6, 10, and 18 weeks, were included. Each age group was divided into five UVR-B dose subgroups. The rats were unilaterally exposed to UVR-B (lambda(max) = 302.6 nm, lambda(0.5) = 4.5 nm). The incident dose on the cornea varied between 0 and 8 kJ/m(2). One week after exposure, the rats were killed, both lenses were extracted, the intensity of forward light-scattering was measured, and photographs were taken. The sensitivity of the lens to UVR-B was estimated as the maximum acceptable dose. RESULTS: The maximum acceptable dose for 3-, 6-, 10-, and 18-week-old rats was estimated to be 1.4, 2.7, 4.3 and 5.2 kJ/m(2), respectively. CONCLUSIONS: Young rats were more sensitive to UVR-B than old ones. Age should be considered when estimating the risk for UVR-B-induced cataract.
PURPOSE: To investigate the effect of age on ultraviolet radiation-B (UVR-B)-induced cataract and to detect the maximum acceptable dose in rats of different age groups. METHODS: Four age groups of 20 rats each, aged 3, 6, 10, and 18 weeks, were included. Each age group was divided into five UVR-B dose subgroups. The rats were unilaterally exposed to UVR-B (lambda(max) = 302.6 nm, lambda(0.5) = 4.5 nm). The incident dose on the cornea varied between 0 and 8 kJ/m(2). One week after exposure, the rats were killed, both lenses were extracted, the intensity of forward light-scattering was measured, and photographs were taken. The sensitivity of the lens to UVR-B was estimated as the maximum acceptable dose. RESULTS: The maximum acceptable dose for 3-, 6-, 10-, and 18-week-old rats was estimated to be 1.4, 2.7, 4.3 and 5.2 kJ/m(2), respectively. CONCLUSIONS: Young rats were more sensitive to UVR-B than old ones. Age should be considered when estimating the risk for UVR-B-induced cataract.