PRVEP P100潜伏时、空间频率阈值与视敏度关系法医学探讨

A study on the relationship between visual acuity and the latency and spatial fequency of P100 of pattern reversal visual evoked potentials in a view of forensic science

目的通过研究眼损伤后不同空间频率下阈刺激时图形翻转视觉诱发电位(PRVEP)相关指标与视敏度之间的关系,试图探讨运用视觉诱发电位推算视敏度的方法及价值。方法对四川大学华西医院眼科门诊钝性眼外伤病例81眼以及正常对照眼(199眼)进行图形翻转视觉诱发电位检查,采用不同空间频率的刺激产生视觉诱发电位波,记录各阈刺激时P100潜伏时与波幅。采用统计学方法描述检测结果,并进行线性相关与回归分析。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,可以通过建立两者之间的相应回归方程用以推算视敏度;各组阈刺激时PRVEP P100潜伏时(X)与视敏度(Y)的对数值存在较好相关性。结论建立相应的回归方程推算视敏度是一种较客观、准确的方法,在常规眼科检查的基础上,有利于客观、准确地评定视功能障碍。

Objective To investigate the relationship between the parameter of P100 elicited by pattern stimuli, spatial frequency and visual acuity in the posttraumatic eyes. Methods 81 eyes sustained blunt injury in outpatients were enrolled from West China Hospital, Sichuan University. The control group was composed of 199 eyes without disease or trauma. Different P100 wave including amplitude and latency were recorded in each eye stimulated by reversal pattern with 5 - sized checkerboards. The data were processed by SPSS to describe the relationship between the visual acuity and the parameter of P100 wave. A linear and regression analysis was done in the statistic procedure. Results There was a high correlation between spatial frequency （X） and the log visual acuity （Y）. Regression equations were deduced for evaluating the visual acuity. There was a correlation between the latency of P100 wave （X） and the log visual acuity （Y） in all the examined eyes. Conclusion The established regression equations can be used to evaluate the visual acuity as an accurate and objective method. There is a promising future of its application in the forensic clinical authentication of visual function.