Retinal Neurodegeneration in Diabetes: an Emerging Concept in Diabetic Retinopathy

Abstract

Purpose of Review: Diabetic retinopathy (DR), the leading cause of blindness in working-aged adults, remains clinically defined and staged by its vascular manifestations. However, early retinal neurodegeneration may precede vascular pathology, suggesting that this neuronal damage may contribute to disease pathogenesis and represent an independent target for intervention. This review will discuss the evidence and implications for diabetic retinal neurodegeneration. Recent Findings: A growing body of literature has identified progressive retinal thinning and visual dysfunction in patients with diabetes even prior to the onset of DR, though advances in retinal vascular imaging suggest that vascular remodeling and choroidal changes occur during these early stages as well. Animal models of diabetes and in vitro studies have also suggested that diabetes may directly affect the retinal neural and glial tissue, providing support to the concept that diabetic retinal neurodegeneration occurs early in the disease and suggesting potentially relevant molecular pathways. Summary: Diabetic retinal neurodegeneration may represent a “preclinical” manifestation of diabetic retinal disease and remains an active area of investigation. As the natural history and molecular mechanisms become increasingly understood, it may lead to upcoming developments in not only the treatment options but also the clinical definition of DR.