[What is the etiology of diabetic retinopathy?].

Recent experimental and clinical investigations suggest several pathogenetic mechanisms for diabetic retinopathy. The pathogenesis of diabetic retinopathy can best be understood by a concerted action of biochemical, hemodynamic and endocrine or cytokinetic factors. Biochemical factors such as nonenzymatic glycosylation and induction of the aldose reductase pathway seem to be of importance for the genesis of nonproliferative diabetic retinopathy, characterized by pericyte loss, basal membrane thickening and formation of microaneurysms. The development of the proliferative form, characterized by ocular neovascularization, is the response to chronic hypoxia and is probably due to the angiogenetic influence of hormones and growth factors. The most important therapeutic approach is strict control of hyperglycemia.