To investigate the role of DDAH1 and DDAH2 in angiogenesis in choroidal neovascularization (CNV), a feature of age-related macular degeneration, we measured the extent of CNV induced by laser-rupture of Bruch’s membrane in heterozygous DDAH1 and homozygous DDAH2 deficient mice. The gene discussed is DDAH1; the disease is age-related macular degeneration.