Pathophysiology of diabetic retinopathy

Several interacting and mutually perpetuating biochemical pathways or systems, such as the polyol pathway, nonenzymatic glycation, oxidative stress, protein kinase Cbeta and the renin-angiotensin system, may be activated as a result of sustained hyperglycemia in diabetes. These abnormally activated pathways may in turn influence several vasoactive factors and cytokines, such as vascular endothelial growth factor, interleukin-6. pigment epithelium-derived factor and endostatin, which are important in mediating the functional and structural changes of diabetic retinopathy. Intricate and interacting regulatory mechanisms involving these factors may control their ultimate ability to produce biologically significant effects. A better understanding of these factors and their interactions may assist in the development of adjuvant therapies for the treatment of diabetic retinopathy. (C) 2002 Prous Science, All rights reserved.