缺血性视神经病变的视诱发电位

THE VISUAL EVOKED POTENTIALS IN ISCHEMIC OPTIC NEUROPATHY

本文用图形翻转刺激形式,对27例(37眼)缺血性视神经病变(ION)作了 VEP 的临床分析,并结合视野(VF)和对比敏感度(CS)进行了比较观察。ION 的 VEP 主要表现为振幅下降伴潜伏期轻度延长,VEP 潜伏期和振幅的异常率分别为83.5%和81.3%。ION 的 CS 主要表现为中、高频和全频下降,VEP 的振幅与 CS呈有意义的相关。ION 的 VF 损害多数为象限性缺损和弓形暗点,VEP 的异常与中心视野缺损有关。对其中7例8眼随访的 VEP 振幅有所下降。以上结果表明,ION 是一种导致多种视功能受损的眼病。

In this study the pattem-reversal sti- mulation was used for analysing the clinical VEP in 27 cases(37 eyes)of ischemic optic neuropathy (ION),and combined uses of visual field(VF)and contrast sensitivity(CS)examinations were compared and observed,with 3 kinds of spatial frequencies (60′,30′,15′ check size),VEP in the eyes of ION displayed decrease in amplitude as a dominant ma- nifestation accompanied by the slight increase of la- tency period.The abnormal latency and amplitude were 83.5% and 81.3% respectively.The decreased CS in the ION eyes was appeared mainly in the sti- mulation of middle and high frequencies or all fre- quency bands.There was a significant correlation be- tween the VEP amplitude and CS in the patients with ION.The qundrant VF defect and bow-shaped scotoma were displayed in majority of the cases. Abnormal VEPwas shown to be related to the cen- tral VF impaired.Among these patients,7 cases (8 eyes)were followed up with VEP,however the VEP amplitude was shown decreasing somewhat compaired with first exam.The results indicated that the ION was responsible for many visual func- tion damages.