Diabetic retinopathy (DR) is a main cause of blindness throughout the world, with chronic hyperglycemia and arterial hypertension being the key contributors to the development of this microvascular complication. A few international multicentre studies have recently been conducted to assess effect of intensive control of glycemia and AH on the development and progress of DR in type 1 and 2 DM patients. Results of DCCT, UKPDS, DIRECT, ADVANCE, and AdREM studies are reviewed.