MORPHOLOGICAL AND BIOCHEMICAL-CHANGES IN LENSES OF GUINEA-PIGS AFTER VITAMIN-C-DEFICIENT DIET AND UV-B RADIATION

The effect of ultraviolet B (UV-B) radiation and a vitamin-C-deficient (VCD) diet on guinea pig lenses was investigated. The initial lens ch anges in the VCD group were observed by slit-lamp examination 6 weeks after the start of the VCD treatment; after 12 weeks the changes in th e posterior subcapsular region became more prominent, and the dissocia tion around the posterior suture became wider and slightly deeper towa rd the posterior cortex. The high concentration of lens oxidized gluta thione (GSSG), and the low ratio of reduced glutathione (GSH) to oxidi zed glutathione (GSH/GSSG) on the lens posterior region correlated wit h density changes in the corresponding layers as measured by Scheimpfl ug images with linear microdensitometry. It is suggested that the stro ng oxidative stress of the VCD diet caused the damage at the posterior part of the lens. UV-B radiation appeared to accelerate cataract prog ression in lenses that lack vitamin C.