HIF1A and retinopathy of prematurity: A several fold rise was observed in the levels of RAS components such as renin (5 folds), angiotensinogen (6 folds), ACE (10 folds), ANG II (8 folds) and angiogenic cytokines such as VEGF (12 folds) and HIF-1α (7 folds) in the vitreous humor of infants with ROP as compared to the vitreous of infants operated for congenital cataract.