New concepts on diabetic retinopathy: neural versus vascular damage

Diabetic retinopathy is the leading cause of irreversible legal blindness in working-age adults. The number of people worldwide at risk of developing vision loss from diabetes is predicted to double over the next 30 years. Some elements suggest that neurodegenerative changes occur beyond vascular damage. These changes include increased apoptosis, glial cell reactivity, microglial activation, and altered glutamate metabolism, and could explain some of the functional abnormalities that begin soon after the onset of diabetes, as early changes in electroretinogram. This review article will present some evidences that point out neurodegeneration as a possible initial event in diabetic retinopathy.