Prevention of diabetes-related retinal microangiopathy with aldose reductase inhibitors.

Before any clinical signs of diabetic retinopathy can be detected, two major histopathological lesions occur in the walls of retinal capillaries: basement membrane thickening; and loss of intramural pericytes (mural cells). A decrease in the number of pericyte to endothelial cell junctions also occurs under diabetic conditions and may result in subsequent proliferation of endothelial cells and microaneurysm formation. Aldose reductase inhibitors prevent all these diabetic microangiopathies of the retina in animal models of diabetes and are presently being tested in clinical trials on diabetic retinopathy. Utilization of aldose reductase inhibitors is a novel approach which would potentially provide a very effective diabetic therapy to be used in addition to insulin.