VEGFA and sickle cell disease: To evaluate the expression of the HIF-regulated angiogenic mediator, ANGPTL4, in the eyes of patients with known PSR, we examined 5 paraffin-embedded autopsy eyes from 5 non-diabetic patients sickle cell disease with untreated PSR (i.e., no prior history of scatter laser photocoagulation or intravitreal anti-VEGF therapy), and no history of another ischemic retinal disease.