title: Letter: Ethambutol and the eye; zinc and copper.
mesh_terms: D000818:Animals; D003300:Copper / Q000097:blood / Q000172:deficiency*; D004977:Ethambutol / Q000008:administration & dosage / Q000009:adverse effects*; D006801:Humans; D012162:Retinal Degeneration / Q000139:chemically induced*; D015032:Zinc / Q000097:blood / Q000172:deficiency*
chemical_list: D003300:Copper; D004977:Ethambutol; D015032:Zinc