Advances in the treatment of diabetic retinopathy

As the diabetes epidemic in the United States continues to worsen, so too does the prevalence of diabetic retinopathy (DR). DR is divided broadly into nonproliferative and proliferative stages, with or without vision-threatening macular edema. Progression to proliferative DR is associated with vision loss that is often irreparable, and a rapid decline in health-related quality of life. Vascular endothelial growth factor (VEGF)-A is upregulated in the diabetic eye, and has been identified as a key driver of DR pathogenesis. With this perspective, we review the published phase III clinical trial data of anti-VEGF therapies approved for the treatment of DR in the United States. Using the Early Treatment Diabetic Retinopathy Study Diabetic Retinopathy Severity Scale, in which an improvement of ≥2 steps is considered clinically significant, approximately one-third of patients with DR and macular edema experience this level of improvement after 1 year of treatment with either ranibizumab or aflibercept. The rates of clinically significant DR improvement with ranibizumab could be twice that in the subgroup of patients with moderately severe or severe nonproliferative DR and macular edema. These clinical trial data indicate that intraocular inhibition of VEGF is a rational approach for the management of DR.