Diabetic eye disease

Abstract

Diabetes mellitus is a universal disease that has been associated with a significant increase in incidence among all regions of the world and in all races, ages, and sexes over the last several decades. If the same explosion of the disease continues, it is estimated that there will be over 350 million diabetics worldwide in 2030. Over 30 % of diabetic patients have some form of diabetic eye disease, mostly diabetic retinopathy (DR). Diabetic retinopathy is the leading cause of preventable blindness among individuals of working age, and a major cause of vision loss in the elderly population. Visual loss develops secondary to complications of DR such as diabetic macular edema and ischemia, vitreous hemorrhage, and retinal detachment. Glaucoma, another common cause of blindness, also occurs more often in diabetics and carries a worse prognosis compared to nondiabetics. Although the pathogenesis is not completely understood, diabetes is a widespread microangiopathy associated with pericyte-deficient small vessels and "degenerating" capillaries that gradually interfere with the circulation everywhere in the body. For example, the retinal and glomerular vessels are both affected with microangiopathy in patients with type 1 and type 2 diabetes mellitus and present similar morphologic alterations. In DR, capillary degeneration and occlusion initially happen in isolated channels without clinical significance. Later however, more capillaries become occluded and the circulation is disrupted and the retina eventually becomes ischemic. In addition to pathogenic and epidemiologic aspects of the disease this chapter covers the up-to-date methods to diagnose, monitor, and treat DR.