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

Backgrou nd: 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 mu m) was significantly thinner (P < 0.001) compared with uninvolved eyes (95.1 +/- 13.9 mu m). 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 mu m) 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.