Introduction:

Diabetic retinopathy is estimated to affect one-third of people with diabetes. The prevalence and severity are affected by the duration of diabetes, glycemic control, and the presence of concurrent hypertension. DME can affect up to 7% of patients with diabetes and is the most common cause of moderate visual loss in diabetic patients.

Clinical Features:

The classic clinical descriptions of DME includes focal, diffuse and cystoid (CME), based on the clinical and angiographic appearance (Fig. 13.2.1). Focal macular edema is characterized by focal leaking microaneurysms giving a well-circumscribed area of thickening often associated with hard exudates. Diffuse macular edema is characterized by more widespread vascular abnormalities giving larger areas of thickening, a paucity of hard exudates and cystic changes in the retina. CME associated with DME appears similar to CME from other causes. It is not unusual for affected eyes to manifest two or all three of these sub-types.

OCT Features (Figs 13.2.2 and 13.2.3):