Diabetic Retinopathy

Diabetic retinopathy is a complication of diabetes that leads to legal blindness in many people. It has been characterized as a disease of the retinal vasculature, which loses its blood-retinal barrier properties, leading to edema. But diabetes also induces a number of pathological changes within the neural retina, including apoptosis and glial malfunction. The increase in apoptosis becomes significant very soon after the onset of hyperglycemia and remains higher than normal throughout the duration of diabetes. The glial cells of the retina also become less able to metabolize glutamate into glutamine, and expression of glial fibrillary acidic protein increases. Together these changes suggest that diabetes causes a chronic loss of neurons in the inner retina, much like neurodegenerative diseases of the central nervous system, and that glutamate-induced excitotoxicity may be responsible for the neuronal cell loss. Projects to study the way that diabetes alters glutamate metabolism in the retina, and the potential for neuroprotective drugs to reverse diabetic retinopathy are currently underway.