Therapeutic potential of anti-oxidants and diabetic retinopathy

Retinopathy, a severely disabling complication of diabetes mellitus, is tod ay the leading cause of acquired blindness among young adults in developed countries. Good glycaemic control can attenuate the development of diabetic retinopathy but such metabolic control is often difficult to achieve and m aintain and additional therapies need to be identified by which retinopathy can be prevented or arrested. Hyperglycaemia plays a critical role in the development and progression of retinopathy, but the mechanism by which hype rglycaemia results in the development of retinopathy is not clear. Oxidativ e stress is increased in the retina in diabetes. The possible sources of in creased oxidative stress might include increased generation of free radical s or impaired anti-oxidant defence system. Dietary supplementation with ant ioxidants in animal models of diabetic retinopathy inhibits retinal metabol ic abnormalities and retinal histopathology, suggesting that oxidative stre ss is associated with the development of retinopathy. The mechanism by whic h anti-oxidants inhibit retinopathy in diabetes warrants further investigat ion, but animal studies show that increasing the diversity of anti-oxidants provides significantly more protection than using any single anti-oxidant. Thus, supplementation with anti-oxidants represents an achievable adjunct therapy to help preserve vision in diabetic patients.