Ocular Toxicity of Ethambutol During Both Intensive and Continuation Phases of Anti-Tubercular Therapy in Children

ABSTRACT

Objective: The study was conducted to evaluate the ocular toxicity of ethambutol given in both intensive and continuation phases of treatment in children with drug-sensitive tuberculosis. Methods: A prospective study of 94 eyes from 47 patients receiving an ethambutol-containing regimen was conducted between 1 December, 2018 and 31 August, 2020. Visual acuity, visual field, visual evoked response (VER), contrast sensitivity, colour perception, and retinal nerve fiber layer (RNFL) thickness [using optical coherence tomography (OCT)] were tested for each patient before, during, and after the treatment. Results: On follow-up, visual acuity, color vision, contrast sensitivity, fundus, and visual fields were not affected in any of the patients. There was no statistically significant increase in the mean latency of the P(100) wave at any point in time. On OCT, no significant loss of mean RNFL thickness was detected. Conclusions: Ethambutol is safe to use up to a dose of 20 mg/kg/day throughout the entire course of anti-tubercular therapy in children with drug-sensitive tuberculosis