Kaufmann M, Stodtmeister R, Pillunat L, Wilmanns I
Universitäts-Augenklinik, Ulm/Donau.
Fortschr Ophthalmol. 1990;87(1):32-6.
Transient visually evoked cortical potentials were recorded during an artificial stepwise rise of intraocular pressure. At each pressure step one average was taken. The reversal rate was 1.9 Hz. Two groups of 30 healthy volunteers each were examined: in group one 25 sweeps were averaged and in group two 50 sweeps. Thus the recording time in group two was doubled compared to group one. When all subjects were examined the evoked potentials of the 30 subjects were averaged at each pressure step: the results was a "Grand Average" at the different pressure steps applied. The amplitudes of N2-P2 were plotted versus the intraocular pressure. It is seen that a not monotone or weakly monotone function in the amplitude/pressure curve is more clearly seen in the averages of 25 sweeps. We interpret this result as follows: a not monotone or weakly monotone behaviour is a sign of autoregulation in the optic nerve head. This sign is more clearly shown at a short recording time. The majority of healthy persons show autoregulation, the majority of glaucoma patients do not. According to the results presented here it is advisable to apply short recording times in clinical pressure tolerance testing of the optic nerve head. A short recording time enhances the accuracy of the test.
在眼内压人工逐步升高期间记录瞬态视觉诱发电位。在每个压力步长下进行一次平均。反转率为1.9赫兹。对两组各30名健康志愿者进行了检查：第一组平均25次扫描，第二组平均50次扫描。因此，第二组的记录时间是第一组的两倍。当对所有受试者进行检查时，在每个压力步长下对30名受试者的诱发电位进行平均：结果是在应用的不同压力步长下的“总体平均值”。绘制N2 - P2的振幅与眼内压的关系图。可以看出，在25次扫描的平均值中，振幅/压力曲线中的非单调或弱单调函数更清晰可见。我们对这一结果的解释如下：非单调或弱单调行为是视神经乳头自动调节的标志。这一标志在短记录时间时更明显。大多数健康人表现出自动调节，大多数青光眼患者则没有。根据此处给出的结果，在视神经乳头的临床压力耐受性测试中建议采用短记录时间。短记录时间可提高测试的准确性。
