RESUMO
BACKGROUND: Ganglion cell inner plexiform (GCIP) layer thinning following acute optic neuritis (ON) is well-known. However, the onset of changes in the outer retinal layers needs further study. In this study, we determine longitudinal changes in retinal layer thickness in ON. METHODS: Thirty ON patients underwent optical coherence tomography (OCT) and visual function testing at baseline, one month, and 6 months. RESULTS: Mean GCIPL thickness decreased at one month relative to baseline from 63.6 ± 7.5 µm to 57.3 ± 6.8 µm in 3 mm ring (P < 0.001). There were no significant changes in GCIPL thickness between one and 6 months (P = 0.42). Outer nuclear layer (ONL) thickness in the 6 mm macular area increased from 58.9 ± 5.8 µm to 63.2 ± 6.8 µm at one month (P < 0.001) and then decreased at six month (58.8 ± 5.8 µm) relative to one month, reaching the baseline thickness. While GCIPL thinning at 1 month correlated with baseline visual acuity, change in the central ONL thickness from baseline to month 1 predicted visual outcome at month 6 (r = 0.6, P = 0.001). CONCLUSIONS: Following ON, transient changes occur in the photoreceptor nuclei layer and then revert to baseline. This finding could predict 6 month visual acuity after ON.
