Purpose. The anatomy of the eye and the pathogenesis, clinical features, and prevalence of vision impairment from diabetic retinopathy are described. Screening and risk factors for and treatment of diabetic retinopathy also are addressed.

Summary. The macula and fovea play a critical role in vision. Several interrelated biochemical pathways involving aldose reductase, advanced glycation end products, and protein kinase C link chronic hyperglycemia with retinal capillary endothelial cell damage and dysfunction in patients with diabetic retinopathy. Vision loss and blindness from diabetic retinopathy usually are the result of vascular leakage or ischemia. Screening for retinopathy should be performed within three to five years after the onset of type 1 diabetes and shortly after the diagnosis of type 2 disease, with annual follow-up examinations in both types of diabetes. In patients with diabetic retinopathy, severe vision impairment is less common and less readily corrected than mild vision impairment, and vision impairment is more common and less readily corrected in elderly patients with diabetes than in younger diabetics. Modifiable risk factors for diabetic retinopathy include A1C level, hypertension, cigarette smoking, and dyslipidemia. Tight control of blood glucose concentrations and blood pressure can reduce the risk for and progression of diabetic retinopathy. Aspirin therapy and smoking cessation also are recommended. Dyslipidemia in patients with diabetes is associated with retinopathy progression and vision loss. Treatment of dyslipidemia provides cardiovascular benefits in patients with diabetes, but whether it provides vision benefits remains to be determined. Laser photocoagulation therapy reduces the risk of vision loss in patients with diabetic macular edema, severe nonproliferative diabetic retinopathy, or proliferative diabetic retinopathy. Intraocular surgery may be used for patients with vitreous hemorrhage and retinal detachment of the macula.

Conclusion. Therapeutic approaches used for patients with or at risk for diabetic retinopathy include drug therapy to reduce modifiable risk factors, laser photocoagulation, and intraocular surgery. Screening plays an important role in early detection and intervention to prevent the progression of diabetic retinopathy.