Nonproliferative Diabetic Retinopathy

Abstract

Nonproliferative diabetic retinopathy (NPDR) is a microvascular complication of diabetes mellitus that can lead to irreversible visual loss. Intraretinal microvascular changes, such as altered retinal vascular permeability and eventual retinal vessel and capillary closure, characterize NPDR. Macular edema, the most frequent cause of visual loss in NPDR, may result from increased vascular leakage. Retinal hypoxia, secondary to chronic hyperglycemia, triggers the pathologic processes of NPDR. Additionally, there is increasing evidence that inflammatory mechanisms may play a role in the pathogenesis. Systemic factors such as glycemic control, hypertension, and serum lipid level also contribute to the development and progression of NPDR. Prompt and appropriate initiation of laser photocoagulation for macular edema or severe retinal nonperfusion, along with optimal control of systemic factors, can prevent visual loss.