Assessing Visual Function in Patients With Macular Edema

Abstract

Diabetic retinopathy is a major cause of blindness throughout the world and diabetic macular edema (DME) is the leading cause of visual impairment in patients with diabetes. DME is a thickening of the sensory retina resulting from leakage of fluid from capillaries or microaneurysms. The fluid has a tendency to collect in the outer plexiform layer of the retina and may be accompanied by the deposition of hard exudates. The Early Treatment Diabetic Retinopathy Study (ETDRS) demonstrated that laser photocoagulation is an effective treatment for DME.1 The ETDRS based its conclusion on the finding that 24% of untreated eyes lose at least three lines of visual acuity (a doubling of the visual angle) while only 12% of treated eyes suffer the same loss, in a three year follow-up period. Eyes with more severe DME showed a greater treatment effect than eyes with milder DME.