Diabetic retinopathy

Diabetic retinopathy (also known as diabetic eye disease), is a medical condition in which damage occurs to the retina due to diabetes mellitus. It is a leading cause of blindness in developed countries. Diabetic retinopathy affects up to 80 percent of those who have had both type 1 and type 2 diabetes for 20 years or more. In at least 90% of new cases, progression to more aggressive forms of sight threatening retinopathy and maculopathy could be reduced with proper treatment and monitoring of the eyes. The longer a person has diabetes, the higher his or her chances of developing diabetic retinopathy. Each year in the United States, diabetic retinopathy accounts for 12% of all new cases of blindness. It is also the leading cause of blindness in people aged 20 to 64. Nearly all people with diabetes develop some degree of retina damage ("retinopathy") over several decades with the disease. For many, that damage can only be detected by a retinal exam, and has no noticeable effect on vision. Over time, progressive retinal damage may appear on a retinal exam, first with small bulges in retinal blood vessels called microaneurysms. Then larger abnormalities in retinal vessels: cotton wool spots, hemorrhages, lipid deposits called "hard exudates", intraretinal microvascular abnormalities, and abnormal-looking retinal veins. Eventually, many progress to a stage where new blood vessels grow throughout the retina. These new blood vessels often break and bleed. Minor bleeding can cause dark floating spots obstructing vision; major bleeding can completely block vision. Around half of people with diabetic retinopathy develop swelling of the macula, called macular edema, which can begin at any time. If the swelling occurs near the center of the macula, it can cause vision disruptions ranging from mildly blurred vision to severe loss of the center of an affected person's visual field. Left untreated, around 30% of those with such swelling experience vision disruption over the next 3–5 years.