An object of the present invention is to find a novel medicinal use of 2-phenyl-1,2-benzisoselenazol-3(2H)-one or a salt thereof. 2-Phenyl-1,2-benzisoselenazol-3(2H)-one or a salt thereof exhibits an excellent inhibitory effect on neovascularization in the choroid and also has a protective effect on retinal pigment epithelial cell damage, and therefore is useful as a prophylactic or therapeutic agent for age-related macular degeneration.
