Monarch Disease Ontology id MONDO_0018998 (Leber congenital amaurosis) (LCA) is a retinal dystrophy defined by blindness and responses to electrophysiological stimulation (Ganzfeld electroretinogram (ERG)) below threshold, associated with severe visual impairment within the first year of life. Also known as: LCA, Leber's amaurosis, Leber's congenital amaurosis, Leber's disease, amaurosis congenita of Leber.