Early Retinal Nerve Fiber Layer Change of Ethambutol Optic Neuropathy by Optical Coherence Tomography

Ethambutol is widely used as first-line drug, but has serious side effect of optic neuropathy. As previously reported, incidence of ethambutol optic neuropathy is about 1\~2%, there was considerable screening efforts and medical cost is increasing. However, there is no effective treatment of ethambutol optic neuropathy or no definite preventable measure. Moreover, multi-drug resistance tuberculosis or extensively drug resistance tuberculosis is emerging, more toxic secondary drug is used in the long-term. It is known that retinal nerve fiber layer is increased early stage in ethambutol optic neuropathy. So we decide to evaluate the retinal nerve fiber layer thickness measured by optical coherence tomography in longitudinal manner.