Arvind Hemamalini, Klistorner Alexander, Graham Stuart L, Grigg John R
Save Sight Institute, Sydney Eye Hospital, University of Sydney, Marquire Street, PO Box 4337, Sydney, 2001, NSW, Australia.
Doc Ophthalmol. 2006 May;112(3):189-99. doi: 10.1007/s10633-006-0005-y. Epub 2006 Jun 22.
Multifocal visual evoked potentials (mfVEPs) have demonstrated good diagnostic capabilities in glaucoma and optic neuritis. This study aimed at evaluating the possibility of simultaneously recording mfVEP for both eyes with dichoptic stimulation using virtual reality goggles and also to determine the stimulus characteristics that yield maximum amplitude. ten healthy volunteers were recruited and temporally sparse pattern pulse stimuli were presented dichoptically using virtual reality goggles. Experiment 1 involved recording responses to dichoptically presented checkerboard stimuli and also confirming true topographic representation by switching off specific segments. Experiment 2 involved monocular stimulation and comparison of amplitude with Experiment 1. In Experiment 3, orthogonally oriented gratings were dichoptically presented. Experiment 4 involved dichoptic presentation of checkerboard stimuli at different levels of sparseness (5.0 times/s, 2.5 times/s, 1.66 times/s and 1.25 times/s), where stimulation of corresponding segments of two eyes were separated by 16.7, 66.7,116.7 & 166.7 ms respectively. Experiment 1 demonstrated good traces in all regions and confirmed topographic representation. However, there was suppression of amplitude of responses to dichoptic stimulation by 17.9+/-5.4% compared to monocular stimulation. Experiment 3 demonstrated similar suppression between orthogonal and checkerboard stimuli (p = 0.08). Experiment 4 demonstrated maximum amplitude and least suppression (4.8%) with stimulation at 1.25 times/s with 166.7 ms separation between eyes. It is possible to record mfVEP for both eyes during dichoptic stimulation using virtual reality goggles, which present binocular simultaneous patterns driven by independent sequences. Interocular suppression can be almost eliminated by using a temporally sparse stimulus of 1.25 times/s with a separation of 166.7 ms between stimulation of corresponding segments of the two eyes.
多焦视觉诱发电位（mfVEPs）已在青光眼和视神经炎中显示出良好的诊断能力。本研究旨在评估使用虚拟现实护目镜通过双眼分视刺激同时记录双眼mfVEP的可能性，并确定产生最大振幅的刺激特征。招募了10名健康志愿者，使用虚拟现实护目镜以双眼分视的方式呈现时间稀疏模式脉冲刺激。实验1包括记录对双眼分视呈现的棋盘格刺激的反应，并通过关闭特定节段来确认真实的地形图表示。实验2包括单眼刺激并与实验1比较振幅。在实验3中，双眼分视呈现正交取向的光栅。实验4包括以不同稀疏程度（5.0次/秒、2.5次/秒、1.66次/秒和1.25次/秒）双眼分视呈现棋盘格刺激，其中两只眼睛相应节段的刺激分别间隔16.7、66.7,116.7和166.7毫秒。实验1在所有区域均显示出良好的波形，并确认了地形图表示。然而，与单眼刺激相比，双眼分视刺激的反应振幅受到17.9+/-5.4%的抑制。实验3显示正交和棋盘格刺激之间的抑制相似（p = 0.08）。实验4显示，在1.25次/秒的刺激频率且两眼刺激间隔166.7毫秒时，振幅最大且抑制最小（4.8%）。使用虚拟现实护目镜在双眼分视刺激期间记录双眼mfVEP是可行的，该护目镜呈现由独立序列驱动的双眼同时模式。通过使用1.25次/秒的时间稀疏刺激，且两眼相应节段刺激间隔166.7毫秒，几乎可以消除双眼间抑制。
