屈光不正性弱视多导视觉诱发电位地形图的特点

The investigation of multi-channel Visual Evoked Potentials in ametropic amblyopia

目的 :研究屈光不正性弱视多导视觉诱发电位地形图变化的特点。方法 :选取 13.7′、2 7.5′及 5 5′三种方格对正常儿童 (88眼 )及屈光不正性弱视儿童 (4 4眼 )进行多导视觉诱发电位地形图的研究 ,分析枕区五个导联位的P1潜时及N1P1振幅 ,并观察每一例地形图。结果 :13.7′及 2 7.5′方格 ,弱视眼的P1潜时同正常组相比显著延迟 ,弱视眼的N1P1振幅在枕区导联降低 ;在 5 5′方格两组间P1潜时及N1P1振幅差异无显著性意义 ,N1P1振幅的分布同正常组改变。地形图 :枕区高电位活动不对称分布增多。结论 :屈光不正性弱视P1潜时及N1P1振幅的异常 ,主要发生在高空间频率 ,P通道可能受到了视觉发育敏感期异常视觉经验的影响。

Objective:To investigate multi channel Visual Evoked Potentials(VEP)with different spatial frequencies in ametropic amblyopia.Methods:44 controls(88eyes) and 22 ametropic children(44eyes) were studied. Visual Evoked Potentials to 13.7′,27.5′and 55′ check sizes were recorded from 15 scalp derivations,and P 1 latency and N 1P 1 amplitude in 5 derivations as well as the VEP topography of each subject were analysed. Results:There was significant difference in P 1 latencies at all derivations and N 1P 1 amplitudes at O 1,O z,O 2 derivations between control group and ametropic amblyopia group in high spatial frequency(P<0.05),but not in low spatial frequency. It was showed that the ametropic amblyopia had longer P 1 latency and smaller amplitude than normal groups. The distributions of N 1P 1 amplitude had the same feature as the control group at all check sizes. The color mapping showed that there was significant difference in positive activity shift between ametropic amblyopic group and control group(P<0.05).Conclusion:It was suggetsed that ametropic amblyopia may be the reason for the mild development of P pathway.