Abstract

Assessment of ethambutol optic neuropathy by nerve fibre layer and ganglion cell layer analysis using OCT Materials and methods: It was an observational, cross sectional study. Twenty-five patients with history of taking ATT were studied in 1yr duration (Sept 2019-Aug 2020). All patients underwent a neuro-ophthalmic examination including visual acuity, colour vision, visual fields and fundus.OCT was performed on both eyes of each patient using nerve fibre layer and macular analysis protocol. Similar age match control group were taken. Results: Male patients showed dominance (68%).Reduced VA and colour vision defect was observed. Average RNFL thickness in EON patients were 66.00±10.24µm, 94.23±12.23 µm in healthy controls (p<0.0001).In EON patient severe thinning observed in temporal quadrant RNFL thickness (p<0.01).Average GCL±IPL thickness were 64.12±10.22 µm in EON, 83.30±8.32 µm in control group (p<0.0002). Conclusion: A decrease in RNFL thickness was observed in all quadrants in patients with ethambutol induced optic neuropathy, but more pronounced in temporal quadrant. Hence careful use of ethambutol must be analysed.

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