多焦视诱发电位在屈光不正性弱视眼视功能检查中的应用

Multifocal visual evoked potential in isometropic amblyopes

本文用多焦视诱发电位研究屈光不正性弱视眼在视野不同离心度的视功能变化。刺激图形由６１个小六边形组成。刺激野直径约１３．６度。在电脑程序控制下，各六边形同时并互相独立地进行刺激，自动分离提取到各自的反应波形。屈光不正性弱视眼与正常对照眼比较，在刺激图形中心区潜伏期延长，振幅下降，差异有显著性。本研究证实。

This study investigate the variation of visual function in different eccentricities of the visual field in isometropic amblyopes with multifocal visual evoked potential.The stimulus matrix containing 61 hexagons was generated.The diameter of the entire stimulating field was approximately 13 6 deg of arc.The hexagons were simultaneously but independently modulated in time by the controlling computer program.The response contributions from each of the individual stimulus elements could be extracted by Veris system.Our result showed that mean latency is longer in the fovea and in the first ring for the isometropic amblyopes than for the normal(control)subjects.The differences are highly significant at the fovea and in the first ring.In the second ring and the third ring,the difference is not significant.In isometropic amblyopes,the P1 N2 amplitude is about half of that in the normal subjects for the fovea and is similar to that for the normal subjects in the third ring.The P1 N2 amplitudes in the isometropic amblyopes are significant lower than the normal values from the center to the second ring.Our result indicates that in isometropic amblyopia,the attenuation of the visual function are marked in the central region of the visual field and diminished in the periphery.