Protective function of alpha-tocopherol against the process of cataractogenesis in humans

In a random trial 50 patients with unilateral/bilateral idiopathic immature senile cataract (cortical n = 25, nuclear n = 25) requiring surgery at lea st in one eye were included in the present study. Reduced glutathione (GSH) , vitamin E, malondialdehyde (MDA) and glutathione peroxidase (GSH-Px) were studied in these patients receiving either vitamin E (n = 12 in each subgr oup) or placebo (n = 13 in each group) for 30 days. A comparable increase o f vitamin E in both types of lens homogenates of cataractous patients was o bserved in the study group. The level of GSH in cortical cataractous lenses in the study group was significantly raised (p < 0.001) whereas it was not increased significantly in nuclear cataractous tenses (p > 0.05) as compar ed to the placebo group. The percentage decrease in MDA levels was greater in cortical cataracts (38.07%) than in the nuclear type (27.94%). The activ ity of GSH-Px in cortical lenses was higher than that in the nuclear catara ctous lens. The change in the size of lens opacity in cortical cataractous patients receiving vitamin E therapy was significantly decreased as compare d to the placebo group. There may be a direct modulating effect of vitamin E on some GSH-related enzymes and the cortex of the lens might be protected more than the nucleus. Copyright (C) 2000 S. Karger AG, Baser.