GSSG-reducing activity in lenses deficient in glucose-6-phosphate dehydrogenase.

Steroids that inhibit glucose-6-phosphate dehydrogenase (G6PD) were used to examine the correlation between the loss of GSSG-reducing activity and G6PD deficiency in the lens. The correlation was found to be nonlinear. In senile cataracts, which had lost 36% of NADPH-generating activity as compared to clear lenses, the estimated loss of GSSG reduction was only 20%. On the other hand, lenses with severe G6PD deficiency (i.e. 93% loss) retained at least 28% GSSG-reducing activity. The declined reducing activity, however, suggested a possible role of G6PD deficiency in cataract formation in young patients.