Diabetic retinopathy is one of the most common causes of blindness in industrialised countries, affecting the retina of diabetic patients. See Eye Anatomy drawing below to see where the retina is.
Diabetes affects up to 3% of the world population. Diabetic Retinopathy refers to the effect of diabetes on the retina (the light sensitive part of the back of the eye). Not everyone with diabetes gets diabetic retinopathy, but it is related to the duration of the diabetes and the metabolic control of the patients. Patients that control their diabetes poorly can develop retinopathy within a few years whilst patients that control their diabetes well may not develop retinopathy at all.
Diabetic retinopathy affects the small arteries and capillaries in the retina, causing haemorrhages within the retina or to the vitreous cavity and growth of abnormal blood vessels within the retina. It presents with blurred or distorted vision due to vitreous abnormalities and macular oedema. If untreated, late stage proliferation diabetic retinopathy can cause retinal detachment, severe glaucoma (neovascular glaucoma) and blindness.
Early diabetic retinopathy is often asymptomatic. The retina should be screened regularly to detect early background diabetic retinopathy that may progress. Symptoms depend on how advanced the disease is but the main one is visual impairment to some degree.