Objective      To investigate the electrophysiological and clinical characteristics of non-arteritic anterior ischemic optic neuropathy (NAION).       Methods      A total of 28 eyes of 17 patients with NAION from March 2013 to March 2014 were selected to analyze the clinical characteristics including pattern visual evoked potential (PVEP)

fluorescein fundus angiography (FFA)

and visual field (VF).       Results      Among the 28 eyes undergoing PVEP test

the amplitude of P100 wave was decreased differently to 1°  or 15′ temporal frequency stimuli. Latency of P100 wave to 1  temporal frequency stimuli delayed moderately (15 ms) in 5 eyes

and no delay or mild delay (15 ms) was found in the rest 23 eyes. Latency of P100 wave to 15′ temporal frequency stimuli delayed moderately in 6 eyes and there was no delay or mild delay in the rest 22 eyes. Twenty-three eyes of 15 patients performed FFA test

and arm-to-retina circulation time (ART) of 6 eyes (accounting for 24%) was longer than 15 s. Seven eyes showed optic disc hyperfluorescence in the later stage of FFA

and the rest eyes showed hypofluorescence. Among the 28 eyes receiving VF test

10 eyes were normal

7 eyes with decreased visual sensitivity or scotoma (it occurred around the blind spot in 4 eyes)

7 eyes with defects connected with the blind spot

and 4 eyes with limited visual field. The comparative analysis of PVEP and FFA showed that the latency of P100 wave delayed moderately in the patients with optic disk hyperfluorescence in the later stage of FFA

but did not delay in the patients with optic disk hypofluorescence. The comparative analysis of PVEP and VF showed that there were 14 eyes with abnormal VF and abnormal PVEP

7 eyes with normal VF and abnormal PVEP

and 4 eyes with normal PVEP and abnormal VF.       Conclusion      The latency of P100 wave in NAION is mostly normal or mildly delayed

but shows moderate delay when optic disc edema and hyperfluorescence in the later stage of FFA happen. ART delay of FFA is not a sensitive index to confirm NAION. PVEP can help to diagnose NAION when VF is normal.