BackgroundEthambutol (EMB) is one of the first-line anti-tuberculosis therapy. One of its precarious side effects is ethambutol-induced optic neuropathy (EON). The ocular manifestations of EON include painless loss of central vision and cecocentral scotomas in the visual field. Case DescriptionA 60-year old man presented with gradual and painless visual loss since 3 months prior to visit. The accompanying symptoms were frequent headache without double vision and photophobia. He had been diagnosed with pulmonary tuberculosis (TB) for 9 months and consumed EMB for 7 months before being advised to discontinue. There was neither history of systemic diseases nor family history of neuropathy. Examination showed reduced visual acuity with positive relative afferent pupillary defect (RAPD) on right eye. Humphrey test showed bilateral generalized visual loss. Ocular computed tomography (OCT) showed retinal nerve fiber layer (RNFL) thickness was within normal limit. Magnetic resonance Imaging (MRI) brain indicated unremarkable result for optic neuropathy. Based on the examinations listed above, this patient was diagnosed as EON and EMB was stopped immediately. Patient was given oral citicoline 1000mg and zinc supplementation for one month. After 1 st and 3 rd month follow up, patient’s visual function was gradually improved. The ophthalmic examinations indicated recovery of the visual function. ConclusionsThis case suggested that an early detection and intervention in patient with EON has promising result in visual outcome. EON is a reversible optic neuropathy if the ocular toxicity is monitored closely among the tuberculosis patients who are prescribed EMB regiment.

Introduction: The incidence of fellow eye involvement in non-arteritic anterior ischemic optic neuropathy (NAION) is 15% at 5 years after initial onset, although risk factors have not been identified. The aim of this article is to determine the risk factor that could influence the fellow eye involvement with NAION.  Case Report: A 72 year-old male presented with gradual painless vision loss in the left eye (LE) for 3 months. He did not have smoking habit. BCVA on the LE was 3/60 and RAPD was present. Funduscopic examination showed optic disc atrophy on LE. Humphrey test revealed altitudinal pattern on LE with visual field index (VFI) 63%. OCTA showed significant decreased capillary perfusion on LE retinal nerve fiber layer thinning and poor capillary perfusion on LE while the right eye (RE) was normal. Laboratory examination indicated diabetes mellitus, dyslipidaemia, and hypercoagulable state. He was prescribed antidiabetic medication, antithrombotic therapy, and statin. After a month, patient showed improvement in both ocular and laboratory examinations. He was advised to continue treatment until the next visit, but he didn’t comply. Two months later, patient was presented with painless vision loss, edematous optic disc, and altitudinal visual field defect in the RE. Laboratory examination also revealed unsatisfactory results. Discussion: Prior studies discovered that hypercoagulable states potentially contribute to NAION, presumably due to altered blood viscosity, which further leads to vascular occlusion. Our case showed hypercoagulable state patient with increased d-Dimer and fibrinogen level. Antithrombotic therapy was found beneficial to improve patient’s symptoms. However, he did not comply to therapy, thus vision loss of the fellow eye occurred. Conclusion: Non-compliant behaviour of patient could be the risk factor for fellow eye involvement.