Sugar alcohols in the lens epithelium of age-related cataract

We have measured the levels of glucose and sugar alcohols in the lens epithelium of 24 non-diabetic and 21 diabetic patients undergoing extracapsular cataract extraction for age-related cataract. Lens status was assessed preoperatively according to the Lens Opacities Classification System II. In comparison to non-diabetics, the lens epithelia of diabetic patients have increased levels of glucose and sorbitol, and lower content of myo-inositol. Both myo-inositol decrease and sorbitol accumulation are strictly related to the fasting blood sugar level. No correlation or trend was detected in diabetic subjects between myo-inositol or sorbitol level and cataract type. In non-diabetic patients nuclear opacification was associated with a significant increase of myo-inositol level in lens epithelium.