Pathological ocular angiogenesis in diabetes: A perspective of emerging paradigms and current evidence

Diabetes and its complications are a leading cause of morbidity and mortality in developing and developed countries. The control of hyperglycemia, blood pressure, and lipid levels delays these complications. Diabetic macular edema (DME) and proliferative diabetic retinopathy (PDR) are the most sight-threatening complications of diabetes. The established gold standard for high-risk PDR and focal DME is laser photocoagulation. Early Treatment Diabetic Retinopathy Study (ETDRS) and the Diabetic Retinopathy Study provided strong evidence for this modality. Pharmacologic interventions involving modification of mediators of the pathological angiogenesis (aptamers, steroids, macrolides, small interfering RNAs, etc.) and increased understanding of the pathway and mediators has expanded the scientific horizons. The evidence for these interventions is increasingly becoming credible. Improvement in visual acuity in addition to the decrease in retinal thickness is an added advantage derived from many of these drugs. Better laser delivery methods with pattern scanning and short pulse durations along with multi-modality treatment appear appealing. However, multi-centric, multiethnic, head-to-head comparisons of individual modalities alone or in combinations are still required to build an irrefutable body of evidence for management of diabetic retinopathy. The current article briefly reviews the emerging paradigms and current evidence available for understanding and dealing with pathological ocular angiogenesis in diabetes.