Objective: To describe changes in the retinal-nerve-fiber layer (RNFL) in patients diagnosed with ethambutol toxic optic neuropathy (ETON) using optical coherence tomography (OCT). Methods: Ophthalmological examinations were performed in 3 patients diagnosed with ETON. Visual acuity (VA), contrast sensitivity, color vision testing, slitlamp examination, applanation tonometry, dilated funduscopic examination, fundus and disc photography, automated perimetry and OCT were performed. Results: Three patients with ETON had VA ranging from 20/150 to counting fingers (CF). They were unable to resolve contrast sensitivity and discriminate fingers (CF). TWo patients with VA of CF in both eyes had RNFL thinning of 48.8% and 49.5%. A third patient 3 with VA of 20/150 in both eyes showed RNFL thickening of 14.10%. Conclusion: The results suggest that OCT may be useful ancillary procedure in early detection and monitoring of ophthalmological changes due to ETON.
Tomography Optical Coherence