Proliferative diabetic retinopathy (PDR) is the major cause of severe visual loss. Lack of oxygen to the retina (retinal ischemia) results in up-regulation of, in particular, the growth factor vascular endothelial growth factor (VEGF) (3) followed by compensatory retinal proliferations. The neovasculature is fragile and often leads to vitreous hemorrhages or retinal detachment which makes the patient at high risk of irreversible vision loss (4).