Nakamura A, Tabuchi A, Matsuda E, Yamaguchi W
Department of Ophthalmology, Kawasaki Medical School, Okayama, Japan.
Doc Ophthalmol. 2000 Sep;101(2):95-113. doi: 10.1023/a:1026409304135.
We investigated to measure the objective visual acuity using pattern visual evoked potentials (PVEP) to help the diagnosis with psychogenic visual loss (PVL) who ranged in age from 7 to 14 years old. Pattern stimuli consisted of black and white checkerboard patterns (39, 26, 15 and 9') with a visual angle of 8 degrees and a contrast level of 15%. The pattern reversal frequency was 0.7 Hz. This resulted in an average of 100 PVEP per session. Visual acuity of 0.1 was consistent with the 39' pattern, 0.2 with the 26' pattern, 0.5 with the 15' pattern, and 1.0 with the 9' pattern. As the results, five PVL patients could measure visual acuity with this method in the present study. The PVEP is useful in evaluating the visual acuity and helped to diagnose the PVL patients. In addition we used the dynamic topography to study the difference in the results of the PVEP. The dynamic topography obtained from the results of the PVEP was analyzed. The flow type of the P100 component diverged into three types (separated type, hollow type and localized type) in the PVL patients and the normal children. The localized type was observed in 59.1% of normal children and in 56.3% of PVL patients. While the separated type was shown in 6.8% of normal children and in 8.3% of PVL patients. There were not significant differences between the PVL patients and the normal children in each type.
我们进行了一项研究，旨在使用图形视觉诱发电位（PVEP）测量客观视力，以辅助诊断7至14岁的精神性视力丧失（PVL）患者。图形刺激由黑白棋盘格图案（39、26、15和9分视角）组成，视角为8度，对比度为15%。图形反转频率为0.7Hz。每次检查平均可获得100个PVEP数据。视力0.1对应39分视角的图案，0.2对应26分视角的图案，0.5对应15分视角的图案，1.0对应9分视角的图案。结果显示，在本研究中有5例PVL患者能够用这种方法测量视力。PVEP在评估视力方面很有用，有助于诊断PVL患者。此外，我们使用动态地形图来研究PVEP结果的差异。对从PVEP结果中获得的动态地形图进行了分析。在PVL患者和正常儿童中，P100成分的血流类型分为三种类型（分离型、空心型和局限型）。局限型在59.1%的正常儿童和56.3%的PVL患者中观察到。分离型在6.8%的正常儿童和8.3%的PVL患者中出现。PVL患者和正常儿童在每种类型上没有显著差异。
