[Modern understanding of the pathogenesis of pre-proliferative diabetic retinopathy]

Diabetic retinopathy (DR) is a severe and late complication of diabetes mellitus leading, in a majority of cases, to poor vision and blindness. The pathogenesis of DR and of the main diseases is complicated; many of its chains are not explained until now. Hyperglycemia is the key reason of many metabolic disorders in diabetes mellitus resulting in vascular complications. An irreversible glycosylation of proteins and activation of free-radical lipid peroxidation occur under the conditions of a long-term hyperglycemia; it brings about structural changes in the retinal microvessel walls, disorders of hematoretinal barrier and transcapillary metabolism as well as hemodynamic and vasoocclusive changes provoking the development of retinal ischemia.