Purpose: To determine whether the optic disc experiences cupping after an episode of optic neuritis as assessed by optical coherence tomography (OCT).
Methods: A total of 50 patients with unilateral optic neuritis and 50 age- and sex-matched controls were studied. A complete examination, including visual acuity (VA), visual fields, and OCT scanning of the optic nerve head was performed. Mean cup-to-disc (C/D) ratios in the affected eyes were compared with fellow and control eyes.
Results: Mean C/D area ratio (CDAR), C/D vertical ratio (CDVR), and C/D horizontal ratio (CDHR) were significantly larger in the affected eyes compared to fellow (P<0.001) and control eyes (P<0.05). The asymmetry in CDAR, CDVR, and CDHR between both eyes in the patients with optic neuritis was equal to or greater than 0.2 in 24, 28, and 30% respectively. A significant inverse correlation was found between the C/D ratios asymmetry and retinal nerve fibre layer (RNFL) thickness (P<0.05).
Conclusion: A significant increase in C/D ratio can be detected by OCT after unilateral optic neuritis, inversely correlated with RNFL thickness, and VA.