Monarch Disease Ontology entry MONDO_0011979 (adult-onset foveomacular vitelliform dystrophy) (AOFVD) is a genetic macular dystrophy characterized by blurred vision, metamorphopsia and mild visual impairment secondary to a slightly elevated, yellow, egg yolk-like lesion located in the foveal or parafoveal region. Also known as: AOFMD, AVMD, Gass disease, adult-onset foveomacular dystrophy, adult-onset foveomacular dystrophy with choroidal neovascularization, adult-onset vitelliform macular dystrophy, macular dystrophy, vitelliform, type 3, pseudo-Best disease.