Ranchon I, Gorrand J M, Cluzel J, Vennat J C, Doly M
Laboratory of Biophysics, School of Pharmacy, University of Auvergne, Clermont-Ferrand, France.
Curr Eye Res. 1998 Jan;17(1):14-23. doi: 10.1076/ceyr.17.1.14.5250.
ERG responses were measured as a function of Ganzfeld luminance to evaluate functional damage induced by light on rat retinas.
Wistar rats were exposed to a fluorescent light of 1700 lux for 12 h, 24 h, 48 h and 72 h. We recorded ERGs before and one night after exposure, then 3, 8, 15, 22 and 29 days later. The b- and PIII-wave amplitudes were plotted against luminance for each group at each recovery time.
The retinal damage induced by a pupillary illuminance of 1700 lux ranged from low to severe as exposure duration increased from 12 h to 72 h, respectively. We observed an effect immediately after light exposure but no improvement during the recovery period. The b-wave amplitude was reduced by 40, 60, 80 and 90 percent after 12, 24, 48 and 72 h of light exposure, respectively; the PIII-wave amplitude was reduced by 30, 40, 70 and 90 percent after these respective exposures. The Ganzfeld luminance eliciting a 50 microV b-wave amplitude increased significantly with exposure duration, but the luminance eliciting the maximal b-wave amplitude was not dependent on this duration. Hence we suggest that the ERG decrease is due to a reduction in photoreceptor number.
We present a full analysis of the electrophysiological parameters recorded from light-exposed or non-exposed rats. This model is a useful tool to study in vivo retinal degeneration.
测量视网膜电图（ERG）反应随全视野亮度的变化，以评估光对大鼠视网膜造成的功能性损伤。
将Wistar大鼠暴露于1700勒克斯的荧光灯下12小时、24小时、48小时和72小时。在暴露前、暴露后一晚以及之后的第3天、8天、15天、22天和29天记录ERG。在每个恢复时间点，针对每组绘制b波和PIII波振幅与亮度的关系图。
随着暴露持续时间从12小时增加到72小时，1700勒克斯瞳孔照度引起的视网膜损伤程度从轻度到重度不等。光照后立即观察到效应，但在恢复期无改善。光照12小时、24小时、48小时和72小时后，b波振幅分别降低了40%、60%、80%和90%；相应暴露后PIII波振幅分别降低了30%、40%、70%和90%。引起50微伏b波振幅的全视野亮度随暴露持续时间显著增加，但引起最大b波振幅的亮度不依赖于此持续时间。因此，我们认为ERG降低是由于光感受器数量减少所致。
我们对光照或未光照大鼠记录的电生理参数进行了全面分析。该模型是研究体内视网膜变性的有用工具。
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