Definition of Diabetic macular edema
Diabetic macular edema: Swelling of the retina in diabetes mellitus due to leaking of fluid from blood vessels within the macula. The macula is the central portion of the retina, a small area rich in cones, the specialized nerve endings that detect color and upon which daytime vision depends. As macular edema develops, blurring occurs in the middle or just to the side of the central visual field. Visual loss from diabetic macular edema can progress over a period of months and make it impossible to focus clearly. Macular edema in common in diabetes. The lifetime risk for diabetics to develop macular edema is about 10%. The condition is closely associated with the degree of diabetic retinopathy (retinal disease). Hypertension (high blood pressure) and fluid retention also increase the hydrostatic pressure within capillaries which drives fluid from within the vessels into the retina. A common cause of fluid retention in diabetes is kidney disease with loss of protein in the urine (protein...