Objective  To observed and analyze the clinical features of patients with nonarteritic anterior ischemic optic neuropathy (NAION) causes of misdiagnosis. Methods A retrospective case study. From November 2014 to July 2022, 49 NAION patients with 49 eyes diagnosed in Department of Ophthalmology, The First People’s Hospital of Lanzhou were included in the study. All patients were misdiagnosed with other eye diseases at first diagnosis. All eyes were examined by best corrected visual acuity (BCVA), relative afferent pupil defect (RAPD), orbital magnetic resonance imaging (MRI), visual field, optical coherence tomography (OCT), and graphic visual evoked potential (P-VEP). Fluorescein fundus angiography (FFA) was performed in 32 eyes. Clinical and MRI, visual field, P-VEP、FFA features of the patients were retrospectively analyzed. Results There were 31 males and 18 females among the 49 patients. All cases were monocular. Age was (59.3±7.8) years. All of them complained of painless visual acuity loss or occlusion sensation in one eye. There were 12 (24.5%, 12/49) and 37 (75.6%, 37/49) cases with disease duration ＞2 months and ≤2 months, respectively. In 49 eyes, misdiagnosed as optic neuritis, normal tension glaucoma (NTG) or suspected glaucoma, optic disc vasculitis, cataract, diabetic retinopathy, traumatic optic neuropathy and toxic optic neuropathy were 28 (57.1%, 28/49), 11 (22.4%, 11/49), 5 (10.2%, 5/49), 2 (4.1%, 2/49), 1 (2.0%, 1/49), 1 (2.0%, 1/49), 1 (2.0%, 1/49) eyes. 24 (49.0%, 24/49), 16 (32.7%, 16/49) and 9 (18.4%, 9/49) eyes had BCVA＜0.1, 0.1-0.5 and＞0.5, respectively. RAPD was positive in 45 eyes (91.8%, 45/49). There were 37 (75.6%, 37/49) and 12 (24.5%, 12/49) eyes with and without optic disc edema, respectively. Bleeding was observed on and around the optic disc in 15 eyes (30.6%, 15/49). MRI examination showed no obvious abnormality in the optic nerve segments of all affected eyes. OCT showed an increase in retinal nerve fiber layer thickness (307.1±62.1) μm in 37 patients with optic disc edema. The visual field examination showed that 24 eyes (49.0%, 24/49) had typical lower visual field defect connected with the physiological blind spot and circumvented the central fixation point, 6 eyes (12.2%, 6/49) had limited visual field defect connected with the physiological blind spot, and 19 eyes (38.8%, 19/49) had diffuse visual field defect. By P-VEP examination, the amplitude of P100 wave decreased moderately to severely in all affected eyes. There were 24 eyes (49.0%, 24/49) with mild peak delay and 11 eyes (22.4%, 11/49) with moderate peak delay. In 32 eyes examined by FFA, the arteries had early peridisk limitation or diffuse delayed filling, and mid-course fluorescein leakage in the corresponding area. Conclusions The main symptoms of NAION patients are painless visual acuity loss in one eye or occlusion of vision. The main clinical features of NAION patients are visual field defect, retinal nerve fiber layer thickening and visual electrophysiological abnormalities. NAION patients with acute or subacute visual loss accompanied by optic disc edema and/or bleeding are often misdiagnosed as optic neuritis, optic neurovasculitis and other types of optic neuropathy. NAION patients with a disease course of ＞2 months are easily misdiagnosed as NTG.

Citation： Wang Xueqiong, Chen Fei, Li Chen, Wang Yanpeng. Clinical characteristics and analysis of 49 misdiagnosed nonarteritic anterior ischemic optic neuropathy patients. Chinese Journal of Ocular Fundus Diseases, 2023, 39(11): 893-897. doi: 10.3760/cma.j.cn511434-20221009-00534 Copy