头低位卧床对健康人视网膜电图的影响

目的观察在头低位卧床模拟失重状态下视网膜电图（ERG）的变化。方法选取6名男性健康志愿者，-6°头低位模拟失重状态，在受试前、受试第2天及受试第5天测量双眼闪光ERG，按照国际视觉电生理协会的临床电生理标准（2008年修订）记录视杆细胞反应、最大混合反应、振荡电位（OPs）、视锥细胞反应和30Hz闪烁光反应。结果视锥细胞反应及闪烁光反应在受试前后无显著变化（P〉0．05）；视杆细胞反应及最大混合反应波的隐含值有显著改变（P〈0．01），而振幅无明显改变（P〉0．05）；OPs在受试前后各波的隐含值及振幅均有显著改变（P〈0．05）。总和波也有显著改变（P〈0．05）。结论头低位卧床模拟失重状态早期可引起明显的视功能异常。

The influence of head down tilt on electroretinography

Background Influence of weightlessness on visual function has been a hot topic in aerospace medicine field.Electroretinography (ERG) is valuable tool of evaluating visual function.Objective This study aims to observe the influence of head down tilt simulated weightlessness on ERG.MethodHead down tilt for 6° was adopted in 6 healthy volunteers.Flash ERG,including rod response,maxium response,cone response,oscillatory potentials (OPs) and 30 Hz flicker was recorded,and the latency and amplitude from each wave were analyzed before,two days and five days after trial.The record procedure followed the ISCEV standard for full field clinical electroretinography (2008 update).Oral informed consent was obtained from all the subjects prior to the trail.Results No significant differences were detected in the latencies and amplitudes of a,b waves of cone response and 30 Hz flicker among various time points(P＞0.05).The latencies were significantly prolonged in b wave of rod and a,b waves of maxim responses(P＜0.01),but no obvious change was found in amplitudes (P＞0.05).Both the latency and amplitude of all of the wavelets of OPs were considerably among the different time points(P＜0.05-0.01),and the ∑OPs was evidently different among the different time points(P＜0.05).Conclusion Head down tilt simulated weightlessness induce the abnormality of visual function in the early stage.