目的:探讨强光对大鼠血-视网膜屏障功能的影响。方法:大鼠随机分为光照组及对照组,光照组大鼠经散瞳后进行10000lx强光照射(12h光照,12h避光,连续1~14d),对照组只接受自然光线照射。分别于强光照射后第1、3、7、14d摘除相应的光照组和对照组大鼠双侧眼球;并用HE染色观察视网膜各层结构变化,用电镜观察视网膜超微结构变化,用伊凡思蓝(Evans blue,EB)灌注后激光共聚焦显微镜下微循环成像及分光光度法定量检测视网膜微循环通透性变化,来评估血-视网膜屏障变化。结果:大鼠在强光照射1d后就出现视网膜光感受器细胞变性、外节膜盘脱落、外核层厚度变薄等超微结构改变,并随着强光照射持续而逐渐加重,3d后出现光感受器细胞凋亡,至14d时外核层厚度已明显变薄、细胞数也明显减少。大鼠在强光照射1d后视网膜血管就出现EB染料渗漏,至14d时EB染料渗漏最明显。结论:强光照射可导致大鼠视网膜外核层光感受器细胞变性、凋亡,外核层厚度变薄、细胞数减少,血-视网膜屏障结构、功能破坏。
AIM: To investigate the influence on blood-retina barrier after intense light exposure in rats.METHODS: The rats were randomly divided into light exposure group and control group. Rats in light exposure group were exposed in white light( 10000 lux,12h on-off,continuing 1-14d). Rats in control group were only exposed in natural light. The eyes of the rats in the two groups were rem oved when the rats in light exposure group acceptted intense light after 1,3,7 and14 d. We observed the change of retinal structure using hem atoxylin-eosin( HE) staining, and observed the change of retinal ultrastructure using electron m icroscope. We quantified the change of retinal vascular perm eability using laser scanning confocal fluorescence m icroscope and spectrophotom etry after perfusion of Evans-blue,to evaluate the change of blood-retinal barrier.RESULTS: At 1d after intense light exposure, the retinal ultrastructure of rats changed, such as denaturation of photoreceptor cells and falling of m em branous disc outer segm ent and thinning of the outer nuclear layer thickness,and so on; and the longerthe rats exposure to intense light, the m ore serious change of the retinal ultrastructure were found. At 3d later,photoreceptor cells began apoptosis. At 14 d later,the outer nuclear layer becam e thinner obviously,and the num ber of cells reduce obviously. At 1d after intense light exposure,EB leaked from the retinal vascular,and at 14 d later the leaking of EB was m ore obvious.CONCLUSION: The photoreceptor cell of the outer nuclear layer of retina will degenerate and apoptosis,and the outer nuclear layer will be thinner, and the structure and function of blood-retinal barrier will be destroied,if the eyes of rats exposed in intense light.