非动脉炎性前部缺血性视神经病变的电生理及临床特征分析

Electrophysiological and clinical characteristics of non-arteritic anterior ischemic optic neuropathy

目的研究非动脉炎性前部缺血性视神经病变(NAION)的电生理及临床特征。方法收集2013年3月至2014年3月我院确诊为NAION的17例患者28眼,分析其图形视觉诱发电位(PVEP)、荧光素眼底血管造影(FFA)、视野(VF)等临床检查特征。结果 28眼均行PVEP检查,其中21眼P100波幅值在1°或15'空间频率均出现不同程度降低。P100波峰时在1°空间频率5眼中度延迟(>15 ms),其余23眼未见明显延迟或者轻度延迟;15'空间频率时6眼中度延迟(>15 ms),其余22眼峰时未见明显延迟或者轻度延迟(<15 ms)。15患者23眼行FFA检查,其中6患者(40%)患者臂-视网膜循环时间(ART)大于15 s。7眼后期出现高荧光,其余后期呈低荧光。28眼均行视野检查,其中10眼正常,7眼视敏度降低或暗点(4眼集中在生理盲点附近),7眼呈现与生理盲点相连的缺损,4眼残存部分视野。对比分析PVEP和FFA,发现FFA后期高荧光的患眼P100波峰时呈中度以上延迟,后期低荧光患眼的峰时未见明显延迟或轻度延迟。对比分析PVEP和视野,发现14眼VF和PVEP均异常,7眼视野正常时PVEP异常,4眼PVEP正常时而VF异常。结论 NAION的PVEP的P100波峰时大多为正常或轻度延迟,当视乳头水肿、FFA后期视盘高荧光时P100波峰时明显延迟。FFA的ART延长不是NAION的敏感指标。PVEP对于视野正常的患眼有辅助诊断的价值。

Objective To investigate the electrophysiological and clinical characteristics of nonarteritic 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 rest22 eyes. Twenty-three eyes of 15 patients performed FFA test,and arm-to-retina circulation time（ ART） of6 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 in4 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.