Neuropathie optique toxique à l’éthambutol au cours d’une méningite tuberculeuse chez un enfant

Abstract

Toxic optic neuropathy is a severe optic nerve injury that can compromise the prognosis for vision, justifying early clinical and ancillary diagnosis. We report the case of an 11-year-old child being treated for tuberculous meningitis with a combination of ethambutol and three other anti-bacillary drugs, referred for a rapidly progressive bilateral decline in visual acuity. On ophthalmologic examination, the visual acuity was counting fingers within 1ft in both eyes, and bilateral optic disc pallor was noted, without other associated abnormalities. Neurological imaging was unremarkable, with red-green dyschromatopsia and a bilateral cecocentral scotoma. Faced with this clinical and paraclinical picture, we arrived at the diagnosis of ethambutol toxic optic neuropathy, with a multidisciplinary decision leading to a change in the antibacillary treatment protocol. No clinical improvement was noted after 3 months of follow-up. Optic nerve toxicity is rare in children and is classically described as dose- and time-dependent. Ethambutol ocular toxicity is extremely rare in children, and the required action when detected is to discontinue the drug. Reversibility is not always assured, which requires early detection of toxic optic neuropathy by close clinical and ancillary monitoring and, above all, sensitization of the treating physicians (pediatricians, pulmonologists and neurologists).