The commonest cause of blindness in young and middle-aged people in the Western world is diabetes mellitus. Although the mechanism underlying diabetic retinopathy is still not understood, the technology to reduce its progress exists, provided treatment is given at the appropriate time. Doctors caring for patients with diabetes should be familiar with all aspects of diabetic retinopathy as well as the other ocular complications of diabetes. They also need a basic knowledge of the special techniques used in the diagnosis and treatment of diabetic eye disease (fundus fluorescein angiography,...