Ethambutol Chiasmal Toxicity with Bitemporal Hemianopia

Ethambutol is a well recognized antimicrobial agent used as a first line agent in the treatment of tuberculosis. Optic neuropathy is a known complication of ethambutol therapy. Rarely, chiasmal ethambutol toxicity may manifest as a bitemporal visual field deficit. We report an additional case of ethambutol chiasmal toxicity with a bitemporal hemianopia. We also include a review of the medical literature on clinical presentation, pathophysiology, monitoring parameters, treatment, and prognosis of ethambutol toxicity.