NOS3 and Abnormal retinal morphology: Here, we show that suppressed NO formation via the use of the competitive NOS inhibitor, Nω-Methyl-l-arginine (L-NMMA), which inhibits NO formation from all three NOS variants (eNOS, inducible NOS, and neuronal NOS), or an eNOS mutant, S1176A, negates neovascular tuft formation and vascular leakage during retinal disease.