Tuberculosis (TB) remains a global health concern, and administration of ethambutol as mainstay therapy can cause toxic optic neuropathy. Herein, we describe the clinical presentation, diagnostic findings, treatment responses, and visual outcomes in four patients who developed toxic optic neuropathy secondary to ethambutol use during TB therapy.
Detailed clinical evaluations, including visual acuity testing, colour vision assessment, contrast sensitivity, fundus examination, visual field testing, optical coherence tomography, and neuroimaging, were conducted. All patients received adjunctive therapy with coenzyme Q10, methylcobalamin, and zinc after discontinuation of ethambutol treatment. The visual prognosis was different for each patient despite similar management strategies. Ethambutol may cause toxic optic neuropathy with diverse features and prognoses. Therefore, regular evaluation is crucial in patients undergoing anti-TB treatment.