应用PRVEP波形振幅比值评估视力及其法医学意义

Application of PRVEP Waveform Amplitude Ratio to Evaluate Visual Acuity and Its Forensic Significance

目的研究双眼视力比值与其图像翻转视诱发电位(pattern reversal visual evoked potential,PRVEP)P100波形振幅比值之间的相关性。方法选取志愿者47名,测量双眼的视力表视力,采用5分记录法计算视力较差眼与较好眼视力的比值。采用黑白棋盘格PRVEP,选择1°、15′刺激视角,分别记录双眼P100波形的振幅,并计算双眼振幅的比值。采用SPSS 20.0软件分析双眼视力比值与双眼P100波形振幅比值之间的相关性,以双眼P100波形振幅比值为自变量(x)、双眼视力比值为因变量(y)进行线性回归分析并行回代检验。结果双眼视力比值与15′刺激视角下P100波形振幅比值之间存在正相关(Pearson相关系数为0.62,P=0.000),拟合线性回归方程为y=0.090 x+0.846(F=20.954,P=0.000)。双眼视力比值与1°刺激视角下双眼P100波形振幅比值之间无明显相关性(P>0.05)。回代检验结果显示,方程推断所得视力与实际检测视力间差异无统计学意义。结论在单眼损伤的法医学鉴定中,拟合的双眼视力比值与15′刺激视角下双眼P100波形振幅比值的线性回归方程对判断伤眼的视力水平有一定的帮助。

Objective To research the correlation between the visual acuity ratio and pattern reversal visual evoked potential (PRVEP) P100 waveform amplitude ratio of both eyes. Methods Forty-seven volunteers were selected, and the visual chart visual acuity of both eyes was measured. The visual acuity ratio of the eye with poor vision to the eye with better vision was calculated by five grade notation method. The amplitudes of P100 waveforms of both eyes were recorded respectively by using black- and-white checkerboard PRVEP and chosing 1°, 15′ stimulating visual angle, and the ratio of amplitudes between the two eyes was also calculated. SPSS 20.0 software was used to analyze the correlation between the visual acuity ratio and the ratio of P100 waveform amplitudes between the two eyes. Return test and linear regression analysis with the binocular ratio of P100 waveform amplitudes as the independent variable(x)and the binocular visual acuity ratio as the dependent variable (y) were made. Results There was a positive correlation between the binocular visual acuity ratio and the ratio of P100 waveform amplitudes under 15′ stimulating visual angle (Pearson correlation coefficient was 0.62, P= 0.000). The fitting linear regression equation was y=0.090 x+0.846 (F=20.954, P=0.000). There was no significant correlation between the binocular ratio of visual acuity and the binocular ratio of P100 waveform amplitudes under 1° stimulating visual angle (P>0.05). Results of return test showed that there was no statistical significance in the difference between visual acuity estimated by equation and actual detected visual acuity. Conclusion In forensic appraisal of monocular injury, fitting linear regression equation of binocular visual acuity ratio and the binocular ratio of P100 waveform amplitudes under 15′ stimulating visual angle, is helpful for visual acuity level estimation of the injured eye to some extent.