Yu M, Brown B, Edwards M H
Department of Optometry and Radiography, The Hong Kong Polytechnic University, China.
Invest Ophthalmol Vis Sci. 1998 Oct;39(11):2033-40.
To investigate the variation of visual evoked potential (VEP) function at different eccentricities of the visual field in esotropic amblyopes and anisometropic amblyopes.
Data from 5 esotropic amblyopic eyes, 6 anisometropic amblyopic eyes, and 45 control eyes were analyzed. A VERIS system was used to generate a stimulus matrix containing 61 hexagons on a computer monitor. Each hexagon of the display contained a number of small black and white hexagonal patches that reversed in polarity during stimulation according to a pseudorandom binary m-sequence. The VERIS system extracted the local responses by cross-correlating the input and output signals. The latencies and amplitudes of the responses from the central 8.6 degrees of arc in the visual field were analyzed.
In esotropic amblyopia, the multifocal VEP latency is prolonged, and the amplitude is reduced in the central region of the visual field. The mean amplitude is significantly smaller, and the mean latency is significantly longer in the temporal visual field than in the nasal visual field. In anisometropic amblyopia, latencies are markedly prolonged, and the amplitudes of multifocal VEP are attenuated in the central region of the visual field, and these effects are lessened in the periphery.
The results are in agreement with psychophysical studies reporting a greater foveal deficit in amblyopia and a greater visual loss in the temporal field than in the nasal field in esotropic amblyopia.
研究内斜视性弱视和屈光参差性弱视患者在视野不同偏心度处视觉诱发电位（VEP）功能的变化。
分析了5只内斜视性弱视眼、6只屈光参差性弱视眼和45只对照眼的数据。使用VERIS系统在计算机显示器上生成一个包含61个六边形的刺激矩阵。显示器上的每个六边形包含多个小的黑白六边形斑块，在刺激期间根据伪随机二进制m序列改变极性。VERIS系统通过将输入和输出信号进行互相关来提取局部反应。分析了视野中央8.6度弧度范围内反应的潜伏期和振幅。
在内斜视性弱视中，多焦VEP潜伏期延长，视野中央区域振幅降低。颞侧视野的平均振幅明显较小，平均潜伏期明显长于鼻侧视野。在屈光参差性弱视中，潜伏期明显延长，视野中央区域多焦VEP的振幅减弱，且这些效应在周边区域减轻。
这些结果与心理物理学研究一致，该研究报告弱视患者黄斑中心凹缺陷更大，内斜视性弱视患者颞侧视野的视力丧失比鼻侧视野更大。
