Previc F H, Blankenstein M F, Garcia P V, Allen R G
Am J Optom Physiol Opt. 1985 May;62(5):309-21. doi: 10.1097/00006324-198505000-00003.
The visual evoked potential (VEP) in four rhesus monkeys was used to assess the transient loss of visual function resulting from single 100-ms argon laser flashes (476.5 and 514.5 nm) whose energy levels did not exceed the maximum permissible exposure (MPE). VEP's were elicited by high-contrast square-wave test gratings which were phase-reversed at a frequency of 6 Hz, and were recorded using bipolar electrodes implanted in the foveal projection region of area 17. The parameters which were investigated included (1) flash size (focused vs. expanded), (2) position of the electrode's receptive field relative to the position of the flash (0, 1.5, 3.0, and 4.5-deg separation), (3) flash exposure level (50, 5.0, and 0.5% of the MPE), (4) peak wavelength of the test grating (454, 540, and 630 nm), and (5) spatial frequency of the test grating (1.0, 4.0, 6.0, and 12.0 c/deg). The results of the flash-size experiment revealed that the expanded flash, whose retinal diameter was approximately 750 microns, eliminated or severely attenuated the VEP for a longer duration than did the focused flash and also resulted in a more gradual recovery function. The combined results of the flash position and energy level experiments indicated that the effective energy of the focused flash declined rapidly beyond 1.5 deg, but still approximated 4% of its maximum value as far as 4.5 deg from its center. Few, if any, wavelength-specific effects were observed after exposure to either the 476.5- or 514.5-nm flashes, even when the energy of the flashes was reduced to a small fraction of the MPE. Finally, the flash effect was considerably longer in duration for the 12.0 c/deg grating relative to the low and intermediate frequency gratings. In general, the findings suggest that the focused and expanded argon laser flashes produce a VEP suppression whose time course and other characteristics correlate well with those associated with behaviorally observed flashblindness in humans after exposure to intense noncoherent flashes.
利用四只恒河猴的视觉诱发电位（VEP）来评估单次100毫秒氩激光闪光（476.5纳米和514.5纳米）导致的视觉功能短暂丧失，这些闪光的能量水平未超过最大允许暴露量（MPE）。VEP由高对比度方波测试光栅诱发，该光栅以6赫兹的频率进行相位反转，并使用植入17区中央凹投射区域的双极电极进行记录。研究的参数包括：（1）闪光大小（聚焦与扩展）；（2）电极感受野相对于闪光位置的位置（0、1.5、3.0和4.5度分离）；（3）闪光暴露水平（MPE的50%、5.0%和0.5%）；（4）测试光栅的峰值波长（454、540和630纳米）；以及（5）测试光栅的空间频率（1.0、4.0、6.0和12.0周/度）。闪光大小实验的结果表明，视网膜直径约为750微米的扩展闪光比聚焦闪光消除或严重衰减VEP的持续时间更长，并且还导致恢复功能更缓慢。闪光位置和能量水平实验的综合结果表明，聚焦闪光的有效能量在超过1.5度后迅速下降，但在距其中心4.5度处仍约为其最大值的4%。在暴露于476.5纳米或514.5纳米闪光后，即使闪光能量降低到MPE的一小部分，也几乎未观察到特定波长的效应。最后，相对于低频和中频光栅，12.0周/度光栅的闪光效应持续时间长得多。总体而言，这些发现表明，聚焦和扩展的氩激光闪光会产生VEP抑制，其时间进程和其他特征与人类在暴露于强烈非相干闪光后行为上观察到的闪光盲相关特征密切相关。
