Ethambutol Effect on Retinal and Optic Nerve Structural Changes in Toxic Optic Neuropathy Case: A Literature Review

Introduction: Ethambutol (EMB) is one of the first-line antituberculosis drugs that reported to cause toxic effects on the eye structure. This study aims to elucidate the histological mechanism of retinal and optic nerve damage in toxic optic neuropathy cases. Reference Sources: The literature search was conducted in the PUBMED and MEDLINE databases using the latest publication of the 2012-2022 series. Studies Selection: The observational and randomized controlled trial studies analyzing the effect of ethambutol on retinal nerve fiber layer, retinal ganglion layer, inner cell plexiform layer thickness, optic nerve tissue, best-corrected visual acuity (BCVA), color perception, visual evoked response, and patients' visual field were included. Data Extraction Method: Articles that met the inclusion criteria underwent a specific evaluation, whereby the main focus was the ethambutol on retinal and optic nerve tissue. Results: The results showed that ethambutol affects the thinning of the Retinal Nerve Fiber Layer (RNFL), decreasing the amount of Ganglion Cells and changing the optic nerve's histological function by damaging the mitochondria and axonal fiber. Conclusion: It was concluded that ethambutol has adverse effects on retinal and optic nerve tissue due to several mechanisms and significantly affects the patient's visual outcome.