A Rare Incidence of Ethambutol Induced Toxic Optic Neuropathy

Ethambutol induces toxic optic neuropathy (EON), which most typically presents as bilateral symmetrical loss of vision and, due to a lack of early detection and adequate treatment, often causes serious irreversible visual impairment. EON is time and dose dependent. In this case report, we will discuss a 59-year-old female patient who came in with complaints of visual impairment, inclusive of a colour vision defect (dyschromatopsia) and blurred vision (scotoma). Her past medication history includes use of first-line anti-tubercular therapy (ATT) with four drugs: Rifampicin, Isoniazid, Ethambutol, and Pyrazinamide. Pyrazinamide was taken for two months, and other medications (Rifampicin, Isoniazid, and Ethambutol) were taken for a period of seven months. From this case report, we will get a clear picture necessitating continuous monitoring for ocular toxicity.