Prevention of visual loss from diabetic retinopathy.

Despite the results of clinical trials showing the efficacy of panretinal and focal photocoagulation of proliferative retinopathy with high-risk characteristics for severe visual loss and for clinically significant macular edema, retinopathy remains an important cause of visual loss. Because these treatments are associated with cost, may not always prevent visual loss, and may result in complications, other nonsurgical interventions have been sought to prevent visual loss from retinopathy. Data from epidemiological studies showed an association between hyperglycemia, hypertension, and dyslipidemia and the incidence and progression of retinopathy and macular edema in people with diabetes. These findings resulted in a number of clinical trials that have shown the efficacy of intensive control of hyperglycemia and hypertension in reducing the incidence and progression of diabetic retinopathy. Despite these findings, the majority of persons with diabetes fail to achieve American Diabetes Association-targeted guidelines for glycosylated hemoglobin, blood pressure, and lipid levels. Thus, new approaches for achieving normalization of blood glucose levels are needed and new clinical trials are underway to assess these new interventions.