Diabetic retinopathy as a complication of diabetes is a microangiopathy affecting the retinal blood vessels. It is characterized by microvascular occlusion and leakage according to its clinical progression. Vascular endothelium and various blood elements show remarkable dysfunction and changes. There is a strong evidence that genetic factors play certain role in the pathogenesis and progression of diabetic retinopathy, so the high risk diabetics could be selected and the adequate prevention could be applied.