Leber's hereditary optic neuropathy precipitated by ethambutol.
BACKGROUND
Leber's hereditary optic neuropathy (LHON) predominantly affects young men between 10 and 30 years of age. However, two cases of LHON during ethambutol administration have been reported in older men and one case in an older woman. We now report a second case of an older woman in whom administration of ethambutol triggered the development of LHON.


METHODS
A 70-year-old woman received ethambutol, rifampicin, isoniazid, and pyrazinamide for the treatment of tuberculosis.


METHODS
Three months after the beginning of this treatment, a marked decrease in visual acuity occurred in both eyes and ethambutol was discontinued. Her corrected visual acuity was 0.03 in both eyes. There was no hyperemia, swelling of the optic disc, or capillary dilatation in either eye. Centrocecal scotomas were found bilaterally. After 1 month, her visual acuity had further decreased to 0.01, and the scotomas had enlarged. At this time, genetic analysis revealed a point mutation in mitochondrial DNA 11778.


CONCLUSIONS
Ethambutol can be a risk factor for LHON because the number of reported ethambutol-related LHON cases has increased to four, including the present one. Ethambutol administration to patients with a family history of LHON should be avoided.
Ikeda
Asako
A
Department of Ophthalmology, Takarazuka City Hospital, Takarazuka, Japan.
Ikeda
Tomohiro
T
Ikeda
Naohiro
N
Kawakami
Yoshimi
Y
Mimura
Osamu
O
D000368:Aged; D000995:Antitubercular Agents / Q000009:adverse effects* / Q000627:therapeutic use; D004272:DNA, Mitochondrial / Q000187:drug effects / Q000235:genetics; D004977:Ethambutol / Q000009:adverse effects* / Q000627:therapeutic use; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D029242:Optic Atrophy, Hereditary, Leber / Q000139:chemically induced* / Q000175:diagnosis / Q000235:genetics; D009898:Optic Disk / Q000187:drug effects / Q000473:pathology; D017354:Point Mutation; D012307:Risk Factors; D014376:Tuberculosis / Q000188:drug therapy; D014792:Visual Acuity / Q000187:drug effects; D014794:Visual Fields / Q000187:drug effects
D000995:Antitubercular Agents; D004272:DNA, Mitochondrial; D004977:Ethambutol