Lachapelle P
Department of Ophthalmology, McGill University, Montreal Children's Hospital.
Can J Ophthalmol. 1987 Dec;22(7):354-61.
To evaluate the effect of a long period of dark adaptation on the light-adapted electroretinogram (ERG), photopic ERGs were recorded before (light-adapted) and immediately after (light-readapted) 15 minutes of dark adaptation. The amplitude of the b-wave in the light-readapted ERG was 48% +/- 4% of that in the light-adapted ERG, and the peak time of the b-wave in the light-readapted ERG was delayed by an average of 3.49 +/- 1.09 ms. Segmental analysis of the b-wave showed that the last segment of the ascending limb of the b-wave (from the second oscillatory potential [OP] to the peak) was attenuated the most (61% +/- 8%). In fact, the reduction in the amplitude of the last segment alone accounted for more than 60% +/- 13% of the overall reduction observed for the entire b-wave. This last segment appears to correspond to OP4 in the 100- to 1000-Hz recordings. The amplitude of OP4 in the light-readapted ERG was 56.5% +/- 10% of that in the light-adapted ERG, a similar reduction to that observed for the last segment of the 1- to 1000-Hz b-wave. The results strongly support the concept that the b-wave of the photopic ERG may actually represent a composite of potentials whose individual contributions are best visualized when the ERG is recorded with the 100- to 1000-Hz bandwidth.
为评估长时间暗适应对明适应视网膜电图（ERG）的影响，在暗适应15分钟之前（明适应）和之后立即（再次明适应）记录明视ERG。再次明适应ERG中b波的振幅为明适应ERG中b波振幅的48%±4%，再次明适应ERG中b波的峰时平均延迟3.49±1.09毫秒。b波的分段分析显示，b波上升支的最后一段（从第二个振荡电位[OP]到峰值）衰减最为明显（61%±8%）。事实上，仅最后一段振幅的降低就占整个b波观察到的总体降低的60%±13%以上。这最后一段似乎对应于100至1000赫兹记录中的OP4。再次明适应ERG中OP4的振幅为明适应ERG中OP4振幅的56.5%±10%，与1至1000赫兹b波最后一段观察到的降低相似。结果有力地支持了这样一个概念，即明视ERG的b波实际上可能代表多种电位的复合，当用100至1000赫兹带宽记录ERG时，其各自的贡献能得到最佳显现。
