Diabetic macular edema (DME), a further complication of diabetic retinopathy, is a clinical manifestation of a breakdown of the blood-retinal barrier in the form of thickening of the retinal fovea, exudates formation on the retina, and cystoid macular edema. The breakdown mechanism is based on the process of unstabilized vascular integrity, angiogenesis, and inflammation. A combination of these mechanisms, among others, is well known to be implemented by VEGF.