Abstract
Purpose: We present two cases of chronic-phase non-arteritic anterior ischemic optic neuropathy（NAION）where OCT angiography（OCTA）contributed to diagnosis.
Case 1: A 62-year-old man noticed an upper visual field disturbance in his right eye 16 months previously. His best-corrected visual acuity was 1.0 in the right eye and 1.5 in the left. Altitudinal hemianopsia with dense scotoma in the upper visual field was detected using Goldmann perimetry（GP）. His right optic disc was pale. There was no significant finding on late images of fluorescein fundus angiography（FA）. Sectorial radial peripapillary capillary（RPC）reduction was found during OCTA.
Case 2: A 75-year-old man noticed a lower visual field disturbance in his right eye 15 months previously. His best-corrected visual acuity was 0.4 in the right eye and 0.6 in the left eye. Altitudinal hemianopsia with dense scotoma in the inferonasal visual field was detected on GP. His right optic disc seemed to be accompanied by glaucomatous optic neuropathy, but this finding did not account for acute visual field disturbance. No significant findings on FA were observed. Sectorial RPC reduction was found on OCTA.
Results: From the acute altitudinal visual field disturbance in these cases, we suspected NAION. However, optic disc appearance and FA findings did not support this diagnosis. However, once we observed sectorial RPC reduction using OCTA and the corresponding visual field disturbances, chronic-phase NAION seemed possible.
Conclusion: OCTA could be a useful tool for diagnosing chronic-phase NAION.
