HIF1A and ischemia: In this study, we have employed the OIR mouse model for various reasons: 1) This model depicts the human retinopathy of prematurity (ROP); 2) It represents an ischemia-dependent model, which manifests the overexpression of HIF-1, the main causation of retinal ischemia; 3) It manifests retinal vasculopathy, i.e., the development of retinal NV; 4) Ischemia has been implicated in the pathophysiology of age related macular degeneration (AMD) [35].