建立模式翻转视觉诱发电位推算外伤性视神经病变后视敏度的数学模型

目的:探讨运用视觉诱发电位推算外伤性视神经病变视敏度的方法及价值。方法:对四川大学华西医院眼科门诊外伤性视神经病变病例42例42眼进行黑白方格翻转视觉诱发电位检查,刺激时间频率2.9Hz、对比度100%,采用117、59、28、14、7s大小的5个不同空间频率,记录各阈刺激时P1波潜伏期与波幅,采用直线相关与回归等统计分析。结果:阈刺激空间频率(X)与视敏度的对数值(Y)之间关系密切,两者之间的数学模型为Y!=-0.114-0.010X(r=0.756,P﹤0.01),通过PRVEP推算的视敏度与平均视敏度之间无差别(P>0.05)。阈刺激时PRVEPP1波潜伏期(X)与视敏度(Y)的对数值存在较好相关性,回归方程如下:Y!=-1.485 0.008X(r=0.621,P﹤0.01)。结论:在常规眼科检查的基础上,应用PRVEP阈刺激空间频率与视敏度关系的数学模型估算外伤性视神经病变后视敏度有利于客观、准确地判断视功能障碍的程度。

Quantification of pattern reversal visual evoked potentials using mathematical modeling procedures of traumatic optic neuropathy

Objective: To explore the relationship between the parameter of P1 wave elicited by pattern stimuli, spatial frequency and visual acuity in traumatic optic neuropathy. Methods:Forty-two cases of traumatic optic neuropathy were enrolled from West China Hospital, Sichuan University. The reversal pattern grating of five check size(117, 58, 29, 14, 7 min of arc) were used as stimuli. The reversal rate of the stimuli was 2.9 Hz, and the contrast level was 100%. The latency and amplitude of P1 wave were recorded while the threshold stimulus was given. SPSS statistical software was used to describe the datum and analyze the relationship between the spatial frequency and visual acuity. Results: There were high correlation between spatial frequency of stimulate threshold and visual acuity, and between the latency of P1 wave and the visual acuity in all the checked eyes. Conclusion: PRVEPs can be used to evaluate the visual acuity.