Nonarteritic anterior ischemic optic neuropathy, Lamina cribrosa, Optical coherence tomography, Retinal nerve fiber layer, Ophthalmology, RE1-994

Abstract Background Nonarteritic anterior ischemic optic neuropathy (NAION) is one of common optic neuropathies affect optic disc. But the structure of optic disc in NAION remains poorly understood. Our aim was to identify optic disc characteristics of NAION. Methods This cross-sectional study included chronic-stage affected eyes and unaffected eyes from NAION patients and normal eyes from age-matched individuals. Measurements of optic disc and macula from swept source optical coherence tomography angiography (SS-OCTA) were recorded. Besides conventional OCTA parameters, we also manually measured circumpapillary retinal nerve fiber layer (cRNFL) thickness, lamina cribrosa depth (LCD) and prelaminar tissue thickness (PLTT). Additionally, we introduced a new parameter, retinal nerve fiber layer density (RNFLD). Results This study finally included 53 NAION-fellow eyes, 26 chronic-stage NAION eyes and 50 normal eyes. NAION-fellow eyes and NAION eyes showed significantly thicker PLTT compared to normal eyes (p