title: Drug-induced optic neuropathy-TB or not TB.
abstract: Autosomal dominant optic atrophy is an inherited optic neuropathy manifesting with variable penetrance and expressivity. Other genetic and environmental factors are postulated to contribute to more marked visual loss in some affected individuals. Optic neuropathy is also a known adverse effect of ethambutol therapy for tuberculosis. This case report demonstrates an atypical presentation of ethambutol toxicity, with progressive profound loss of vision despite drug cessation. A subsequent diagnosis of autosomal dominant optic atrophy was made when the proband's sons presented with mild visual disturbances and color vision defects, confirmed with electrophysiology and OPA1 gene mutational analysis. This case emphasizes the importance of avoiding potentially neurotoxic therapy in predisposed individuals and the influence of environmental factors in patients with inherited optic neuropathies.
authors.affiliation: Department of Ophthalmology, National Eye Centre, University of Auckland, Auckland, New Zealand.
authors.forename: Monika
authors.initials: M
authors.lastname: Pradhan
authors.forename: Dianne
authors.initials: D
authors.lastname: Sharp
authors.forename: Stephen
authors.initials: S
authors.lastname: Best
authors.forename: Andrea
authors.initials: A
authors.lastname: Vincent
authors.forename: Michael
authors.initials: M
authors.lastname: Vaphiades
mesh_terms: D000328:Adult; D000995:Antitubercular Agents / Q000009:adverse effects*; D001766:Blindness / Q000139:chemically induced; D002648:Child; D003117:Color Vision Defects / Q000139:chemically induced; D004594:Electrophysiology; D004977:Ethambutol / Q000009:adverse effects*; D006801:Humans; D008297:Male; D029241:Optic Atrophy, Autosomal Dominant / Q000175:diagnosis* / Q000235:genetics; D009901:Optic Nerve Diseases / Q000139:chemically induced* / Q000175:diagnosis; D010375:Pedigree; D014397:Tuberculosis, Pulmonary / Q000188:drug therapy*; D014792:Visual Acuity; D014794:Visual Fields
chemical_list: D000995:Antitubercular Agents; D004977:Ethambutol