Management of Diabetic Retinopathy. An Overview

Abstract

Diabetic retinopathy is a highly specific vascular complication of both type 1 and type 2 diabetes mellitus. It remains one of the commonest causes of visual loss in people of working age in developed countries. Both duration of diabetes and glycaemic control are significant risk factors for the development of retinopathy. After 20 years of diabetes, nearly all patients with type 1 diabetes mellitus, and more than 60% of patients with type 2 diabetes mellitus, have some degree of retinopathy. Although at present there is no known cure for diabetic retinopathy and diabetic macular oedema, laser surgery and other therapeutic modalities help minimize the risk of mild and severe visual loss from these conditions and, in some cases, restore useful vision for those patients who have suffered significant visual loss. These therapeutic modalities, particularly laser treatment, are most effective when initiated at the time a person is at high-risk for proliferative diabetic retinopathy or before visual acuity is lost from diabetic macular oedema 1 . The 5-year risk of severe visual loss from untreated high-risk proliferative diabetic retinopathy may be as high as 60%, and the risk of mild visual loss from diabetic macular oedema may be as high as 25 to 30%. Since proliferative diabetic retinopathy and diabetic macular oedema may cause no ocular or visual symptoms when the retinal lesions are most amenable to treatment, the overriding concern is to identify eyes at risk of visual loss and ensure that the patients receive referral for laser surgery at the most appropriate time. Even minor errors in diagnosing the level of retinopathy can result in a significant increase in a personis risk of visual loss. Furthermore, collateral health and medical problems present a significant risk for the development and progression of diabetic retinopathy. These factors include pregnancy 2-4 , chronic hyperglycaemia 5-8 , hypertension 9 , renal disease 7 , hyperlipidemia 10,11 and cardiovascular autonomic neuropathy 12 . Patients with these conditions require careful medical evaluation and follow-up for identification of diabetic retinopathy.