“Neuroimaging in ethambutol induced optic neuropathy: MRI in time can save the vision”

Abstract

Ethambutol is an integral part of Antitubercular therapy (ATT) and is often associated with optic neuropathy, However, neuroimaging of ethambutol induced optic neuropathy has been sparsely reported in the literature. We describe the case of a 45-year male patient, diagnosed as Tuberculous spondylodiscitis and was on ATT. Four months after ATT initiation, he presented with visual blurring in both the eyes with bitemporal hemianopia and central scotomas. Visual evoked potential (VEP) revealed prolonged latencies in N75 and P100 waveforms bilaterally. Magnetic Resonance Imaging (MRI) showed optic chiasma and bilateral optic tract hyperintensities on 3D Fluid Attenuated Inversion Recovery (FLAIR) and 3D Double Inversion Recovery (DIR) sequences. Ethambutol was discontinued immediately. On follow-up after 8 weeks, visual acuity reversed back to normal in both eyes.