Chronic hyperglycemia leads to changes in blood flow, ischemia, increased vascular endothelial growth factor (VEGF) expression, production of oxygen-free radicals, endothelial and pericyte dysfunction, and inflammation, which in turn leads to the two major causes of vision loss in diabetes—diabetic macular ischemia (DMI) and diabetic macular edema (DME) [1–3]. The gene discussed is VEGFA; the disease is diabetic macular edema.