Evaluation of optical coherence tomography angiography changes in nonarteritic anterior ischemic optic neuropathy

Purpose: To study the long-term microvasculature changes at the macula and the optic disk in eyes with nonarteritic anterior ischemic optic neuropathy (NAION). Methods: Patients with acute NAION of less than 6 weeks duration were included. Optical coherence tomography angiography (OCTA) of the macula and the optic disk was performed at baseline, 3 and 6 months and compared with the controls. Results: The mean age of 15 patients was 52.25 (+/- 9.06) years. The whole image superficial peripapillary density (42.49 +/- 5.28) was significantly low when compared to that of control eyes (46.36 +/- 2.09); similarly, radial peripapillary capillary density (49.35 +/- 5.64) was also significantly reduced when compared to controls (53.45 +/- 1.96, P < 0.05). These parameters showed significant progressive decrease at 3 and 6 months (P < 0.05). At the macula, both superficial (41.83 +/- 3.64) and deep macular vasculature densities (47.30 +/- 2.04) were significantly reduced when compared to control eyes (52.15 +/- 4.84 and 55.13 +/- 1.81, respectively). The vascular density at the macula remained stable at 3-and 6-months period. Conclusion: The study shows that the microvasculature in case of NAION is significantly reduced both in peripapillary area and in macular area.