Abstract: Objective To asssess the optimal conditions for establishing the white light-induced retinopathy. Method Firstly, SD rats were exposed to white light for the same irradiation time during daytime or nighttime. Secondly, rats of different genders were exposed to light for the same irradiation time. Thirdly, rats were topically administered with or without tropicamide and then exposed to light. Flash eletroretinogram ( FERG) was recorded to evaluate retinal function after light exposure ( LE) . In addition, rats were exposed to light for 4, 8, 12, 16, 20 and 24 h. FERG was recorded at 7, 14 and 21 days after LE. Hematoxylin and eosin staining of retinas was also carried out. Result There were no changes in rats received irradiation during daytime, but retinal function was remarkably decreased in rats exposed to white light during nighttime. No difference was found in retinal function between male and female rats after receiving LE. There was no difference in retinal function between LE+tropicaine group and LE group. Fourteen and twenty-one days after LE, retinal function was significantly reduced by 30% - 50% and outer nuclear layer ( ONL ) of retina was decreased by about 40% in rats exposed to light for 8 - 20 h. However, visual function was almost completely lost, retinal cells in inner nuclear layer and ONL were obviously disappeared, and ONL thickness was even reduced by about 80% in rats received 24 h irradiation. Conclusion A rat model of white light-induced retinal damage was established to evaluate the effect of drugs on retinal functional and structural damage.

Key words: light exposure duration, retinopathy, flash eletroretinogram, outer nuclear layer, SD rats

摘要： 目的 建立稳定的光诱导大鼠视网膜病变模型。 方法 SD 大鼠在夜间和白昼接受相同时程光照损伤、不同性别大鼠同一时间接受相同时程光照损伤、大鼠散瞳后接受光照损伤,通过检测闪光视网膜电图( FERG) 评估视网膜功能。 大鼠分别接受 4、8、12、16、20 和 24 h 光照损伤后,分别于 7、14 和 21 d 后,进行 FERG 检测和视网膜组织病理学检查。 结果 昼间光照 6 h 对大鼠视网膜功能没有明显损伤,但是夜间光照 6 h 可以使大鼠视网膜功能显著下降。 光照损伤后,雄性和雌性大鼠视网膜功能无明显差异,散瞳组和不散瞳组大鼠视网膜功能无明显差异。光照结束后 14 和 21 d,光照 8 ~ 20 h 的大鼠视网膜功能损伤 30% ~ 50%,视网膜外核层厚度减少约 40%;而光照24 h 的大鼠视网膜功能几乎完全丧失,内核层和外核层细胞明显丢失,外核层厚度减少约 80%。 结论 建立白光诱导大鼠视网膜损伤模型用于评价药物对视网膜功能和组织结构的作用。

关键词: 光照时程, 视网膜病变, 闪光视网膜电图, 外核层, SD 大鼠