Background: Visual recovery after optic neuritis (ON) used to be defined as good, although patients frequently complain of poor vision.
Methods: We carried out a prospective study on 38 consecutive patients with acute ON followed monthly for 6 months and evaluated high- and low-contrast visual acuity (HCVA and LCVA, respectively), quality of vision (National Eye Institute Visual Function Questionnaire-25 (NEI-VFQ-25)), visual fields, and retinal thickness by spectral domain optical coherence tomography (OCT).
Results: We found significant impaired LCVA and color vision in ON eyes 6 months after acute ON, which impact on quality of life. LCVA and color vision were correlated with the thicknesses of the ganglion cell and inner plexiform layer (GCIPL; 2.5% LCVA r = 0.65 and p = 0.0001; color vision r = 0.75 and p < 0.0001) and that of the peripapillary retinal nerve fiber layer (pRNFL; LCVA r = 0.43 and p = 0.0098; color vision r = 0.62 and p < 0.0001). Linear regression models that included the change in the GCIPL and pRNFL thicknesses from baseline to month 1 after onset explained 47% of the change in 2.5% LCVA and 67% of the change of color vision acuity. When adjusting for the value of visual acuity at baseline, predictors of the change in vision from baseline to month 6 achieved similar performance for all three types of vision (HCVA, LCVA, and color vision).
Conclusion: Monitoring retinal atrophy by OCT within the first month after ON onset allows individuals at a high risk of residual visual impairment to be identified.
Keywords: Acute optic neuritis; color vision; multiple sclerosis; optical coherence tomography; perimetry; quality of vision; visual acuity; visual field.