Long-term retinal nerve fiber layer changes following nonarteritic anterior ischemic optic neuropathy

Background: In cases of nonarteritic anterior ischemic optic neuropathy (NAION), retinal nerve fiber layer (RNFL) thickness changes have been described during the first 12 months following the acute event. The purpose of this study was to report on the long-term RNFL changes in these eyes beyond the first year following onset of NAION. Methods: Fourteen eyes of 13 patients with NAION were analyzed in this retrospective observational case series study. Uninvolved eyes served as controls. All patients underwent a complete neuro-ophthalmological examination and repeat measurements of peripapillary RNFL thickness using Stratus optical coherence tomography. Results: On optical coherence tomography scan performed on average 6 months following onset of NAION, the mean global RNFL thickness (59.8 ± 11.8 μm) was significantly thinner (P <0.001) compared with uninvolved eyes (95.1 ± 13.9 μm). In a second optical coherence tomography scan performed on average 13 (range 12-23) months later, the mean global RNFL thickness (58.9 ± 6.5 μm) was not significantly different (P = 0.702) from the first scan. Conclusion: There appears to be no further RNFL loss beyond the first 6 months following an acute event of NAION.