CHAPTER 45 - Diabetic retinopathy

Abstract

Diabetic retinopathy is divided into nonproliferative and proliferative forms. Diabetic macular edema is the most common cause of vision loss in diabetic retinopathy. Vision loss can also occur from macular ischemia, vitreous hemorrhage, and various types of retinal detachments. Risk factors include duration of diabetes, age, diabetic control, renal disease, systemic hypertension and pregnancy. Lower hemoglobin A1c levels are associated with a significantly reduced risk of retinopathy. Juvenile insulin-dependent diabetes should have a dilated exam 5 years after diagnosis. Adult-onset diabetics should be examined at diagnosis. Optical coherence tomography can show macular edema, macular thinning and evaluate treatments. Laser and intravitreal injections are used to treat patients meeting criteria for such. The Early Treatment Diabetic Retinopathy Study determined that macular laser treatment reduces the risk of vision loss in patients with clinically significant macular edema. The Diabetic Retinopathy Study determined that patient with (1) neovascularization elsewhere and vitreous hemorrhage, (2) mild neovascularization of the disc and vitreous hemorrhage, and (3) moderate or severe neovascularization of the disc with or without vitreous hemorrhage should receive panretinal photocoagulation to prevent severe vision loss. Pars plana vitrectomy is indicated in nonclearing vitreous hemorrhage, tractional retinal detachment involving the macula, combined tractional-rhegmatogenous retinal detachment and refractory macular edema.