Ethambutol-Induced Optic Neuritis and Vision Loss: A Case Report.

Ethambutol is a first-line chemotherapeutic agent, which is commonly used in combination with other drugs for the treatment of tuberculosis. Ethambutol-induced optic neuritis is a serious and rare side effect that is either dose or duration-related and causes progressive painless vision loss, and cecocentral scotomas in the visual field. A rare case of ethambutol-induced optic neuritis was reported in a 52-year-old female who was taking anti-tubercular treatment for pulmonary tuberculosis for five months. She presented with painless diminished vision in both eyes. The patient was diagnosed with a rare case of optic neuritis through various examination methods. Ethambutol was stopped and therapy was continued with oral prednisone, zinc, and vitamin B complex being started along with anti-TB treatment. She showed no marked improvement in visual parameters until the last follow-up. The patient died due to cardiopulmonary arrest as a consequence of pulmonary tuberculosis.