[Epidemiology, pathogenesis and therapy of diabetic retinopathy and maculopathy]

Diabetic retinopathy is the most prevalent microvascular complication of diabetes mellitus and affects the majority of patients who have suffered diabetes for at least 20 years. Due to the lack of specific symptoms screening of patients is required for early retinal lesions to be detected. Chronic hyperglycemia plays a predominant role in the pathogenesis of the disease. A common denominator of hyperglycemic vascular injury is the increased production of mitochondrial reactive oxygen species, leading to the activation of protein kinase C, of the aldose reductase pathway, and to the increased formation of advanced glycation end products, with the well-described deleterious effects on the microvasculature. Moreover, hypertension and factors such as puberty and pregnancy can worsen retinopathy. Effective screening and therapy can prevent blindness. A distinction is made between proliferative and non-proliferative diabetic retinopathy and diabetic macula oedema. The professional associations of ophthalmologists and internists have drawn up guidelines for the necessary examinations, for therapy and the appropriate intervals between check-ups. Laser photocoagulation can halt further loss of vision, in particular in cases of proliferative diabetic retinopathy and diabetic macula oedema. Vitrectomy is an operative procedure that can bring about a functional improvement even for patients in advanced stages.