Acute changes in ganglion cell layer thickness in ischemic optic neuropathy compared to optic neuritis using optical coherence tomography

AIM: To elucidate the changes of different ganglion cell layer(GCL) thinning patterns between the optic neuritis(ON) and non-arteritic anterior ischemic optic neuropathy(NAION).METHODS: A prospective, observational study was conducted to evaluate the timing of GCL changes between acute ON and NAION using optical coherence tomography. RESULTS: Thinning on optical coherence tomography in the NAION group occurs as early as 11 d after symptomatic onset of vision loss and follows an altitudinal pattern. The mean superior-inferior GCL thickness difference in the NAION cohort was clinically significant at 5.7 μm in the NAION cohort compared to controls of 0.8 μm(P=0.032), but not significant in the ON group compared to controls with both groups measuring 1.1 μm. Global thinning was significant for the ON group compared to controls at 7.2 μm(P=0.011) but not the NAION group compared to controls at 1.35 μm.CONCLUSION: These findings suggest that future treatments for NAION should be given early, and possibly before 11 d in order to prevent GCL and irreversible vision loss.