快速减压对大鼠多焦视网膜电图的影响

目的 观察快速减压后大鼠多焦视网膜电图(multifocal electroretinogram,mfERG)的变化,探究减压病造成视网膜早期功能损伤的特点.方法 20只大鼠随机分为4组,分别为正常对照(NC)组、安全减压(SD)组、快速减压处理后0 h(RD0)组和6 h(RD6)组,安全减压组、快速减压处理组实验动物暴露于加压舱内,舱内气压在30 s内升至1.0 MPa,维持5.5 min,快速减压组打开放气阀在55 s减至常压,安全减压组采用动物安全减压方案减到常压.采用RETIscan 3.15系统检查一侧眼的mfERG.结果 快速减压后mfERG杂波增加,潜伏期延长,幅值降低,RD0组中央区P1波反应密度低于NC组和SD组,RD6组周边P1波反应密度较RD0组降低.NC组、SD组、RD0组RD6组总和反应P1波幅值分别为(71.1±7.5)、(53.6±9.3)、(38.2±13.1)、(18.4±7.7)μV,各组间幅值的差异有统计学意义(F=17.313,P<0.01).RD0和RD6组各象限P1波反应密度低于NC组,在SN和ST象限中P1波幅值降低,RD0和RD6组在SN和ST象限N1波幅值均低于NC组和SD组,差异均有统计学意义(P<0.05).RD0和RD6组各环区反应密度均低于NC组和SD组,各环区P1和N1波幅值均低于NC组和SD组,RD6组在各环区P1和N1波幅值均低于RD0组,差异均有统计学意义(P<0.05).结论 快速减压会造成大鼠mfERG发生特征性改变,主要累及上方和近视盘区域视网膜.

Effect of rapid decompression on rat multifocal electroretinogram

Objective To observe the effect of rapid decompression on rat multifocal electroretinogram (mfERG) and to explore the characteristics of the retinal function impairment due to decompression sickness at early stage. Methods Twenty rats were randomly divided into 4 groups: normal control (NC) group,safe decompression(SD) group, 0 h and 6 h after rapid decompression(RD0 and RD6) groups. The treated rats in safe decompression group and each rapid decompression group were exposed in hyperbaric cabin and air pressure in the cabin rose up to 1.0 Mpa in 30 s and lasted for 5.5 min. The pressure decreased to normal pressure in 55 s as for the treatment of rapid compression while air pressure of safe decompression decreased to normal pressure according to an animal safe decompression protocol. The mfERG parameters of one eye each rat were recorded by RETIscan 3.15 system. Results Rapid decompression increased noise, delayed latent period and reduced amplitude in mfERG. The topographic map showed that the P1 wave response density in RD0 group was lower than that in NC and SD groups and higher than that in RD6 group in peripheral regions.The amplitudes of sum response density in NC, SD, RD0 and RD6 groups were (71.1±7.5 ), (53.6±9.3), (38.2±13.1 ) and ( 18.4±7.7 ) μV, respectively, and there was statistical difference among them (F= 17.313, P<0.01 ).The P1 wave response densities of RD0 and RD6 groups were lower than that of NC group in 4 quadrants (P<0.05) and the P1 wave amplitudes of RD0 and RD6 groups decreased in supranasal and supratemporal quadrants (P<0.05). The P1 wave amplitudes of RD0 and RD6 groups were less than these of NC and SD groups in supranasal and supratemporal quadrants (P<0.05). In 5 rings, the response densities of RD0 and RD6 groups were lower than these of NC and SD groups (P<0.05) and the P1 and N1 wave amplitudes were less than these of NC and SD groups (P<0.05). The P1 and N1 wave amplitudes of RD6 group were lower than those of RD0 group (P<0.05). Conclusion Rapid decompression can cause characteristic changes of mfERG and the major involved parts are superior retina and juxtaprepapillary region.