Drug causing toxic optic neuropathy is:March 2009

Ans. C: EthambutolCauses of nutritional optic neuropathy include tobacco, ethanol, thiamine, and vitamin B-12.Causes of toxic optic neuropathy include chemicals and drugs, such as methanol, ethylene glycol, ethambutol, isoniazid, digitalis, cimetidine, vincristine, cyclosporine, toluene, and amiodarone.Chloroquine causes loss of vision due to retinal damage. Corneal deposits may also occur and affect vision, but are reversible on discontinuation.