Abstract:

The onset of diabetic retinopathy is characterized by morphologic alterations of the microvessels, with thickening of the basement membrane, loss of inter-endothelial tight junctions and selective loss of pericytes in the early stage, together with increased vascular permeability, capillary occlusions, microaneurysms, and later loss of endothelial cells (EC). Pericytes, can regulate vascular tone and perfusion pressure. When the tight link between pericytes and EC was disrupted by the dropout of pericytes,  which would give rise to new vessels, and cause the first abnormalities of the diabetic eye which can be observed clinically. Hyperglycaemia and local hypertension are known to be a direct cause of pericyte apoptosis and dropout, and intracellular biochemical pathways of the glucose metabolites have been explored. However, the exact mechanisms are not yet fully understood and need further clarification in order to develop new effective drugs for the prevention of retinopathy.