Meng Zhao-jun, Chen Xiao-yong, Zhang Jing, Li Ying, Wang Wei
Department of Ophthalmology, Peking University Third Hospital, Beijing, China.
Zhonghua Yan Ke Za Zhi. 2013 May;49(5):438-46.
To investigate the survival of SD rat retinal cells after irradiated with 460-480 nm wavelength blue light at three different irradiance.
Experimental study. Seventy-six SD rats six weeks old were divided into control group (4 animals) and experimental groups (18 different subgroups) with 4 animals for each group. Healthy SD rats were exposed to the 460-480 nm blue light for 3 or 12 hours on three different irradiance of 0.6, 1.5 and 10.0 W/m(2) respectively. After recovery in darkness for 4 hours, 24 hours or 3 days, retinal tissue was collected after the eyes were enucleated. Hematoxylin-eosin staining was performed to evaluate the general anatomical changes of the rat retinal layers. TdT-mediated dUTP nick-end labeling was performed to detect apoptotic cells and immunofluorescence staining was conducted to illustrate the expression and location of related proteins in Müller cells. The number of ganglion cells was analyzed by one-way ANOVA.
No injury was observed in SD rat retina at the irradiance of 0.6 W/m(2). Retinal cells were damaged with irradiance at 10.0 W/m(2), which mainly affected photoreceptors and retinal pigment epithelial cells, while Müller cells of retinal inner nuclear layer were also involved. Apoptosis began after 4 hours of exposure and peaked at 24 hours. Moderate damage of retina was observed at the irradiance of 1.5 W/m(2) after 12 hours rather than 3 hours exposure. The number of ganglion cells was significantly different among the different groups 3 days after exposure. When the exposure time was 3 hours, the number of retinal ganglion cells under different irradiance at 0.0, 0.6, 1.5 and 10.0 W/m(2) was respectively 41.42 ± 0.17, 40.58 ± 0.50, 40.92 ± 0.32 and 22.83 ± 0.79 (F = 1305.86, P = 0.000). When the exposure time was 12 hours, the number of retinal ganglion cells under different irradiance at 0.0, 0.6, 1.5 and 10.0 W/m(2) was respectively 41.42 ± 0.17, 40.83 ± 0.69, 41.08 ± 0.17 and 22.75 ± 0.83 (F = 1095.78, P = 0.000). The number of retinal ganglion cells showed significant decrease 3 days after exposure at the irradiance 10.0 W/m(2) (exposure time 3 h:t = 52.32, P = 0.000; exposure time 12 h:t = 47.58, P = 0.000).
The safe exposure time to SD rat retina layers is 12 hours for the blue light with wavelength 460-480 nm at the irradiance 0.6 W/m(2). And the safe exposure time descends to 3 hours at the irradiance 1.5 W/m(2).
研究460 - 480nm波长蓝光在三种不同辐照度下照射后SD大鼠视网膜细胞的存活情况。
实验研究。将76只6周龄的SD大鼠分为对照组（4只）和实验组（18个不同亚组），每组4只。健康的SD大鼠分别在0.6、1.5和10.0W/m²三种不同辐照度下接受460 - 480nm蓝光照射3小时或12小时。在黑暗中恢复4小时、24小时或3天后，摘除眼球后收集视网膜组织。进行苏木精-伊红染色以评估大鼠视网膜各层的大体解剖学变化。进行TdT介导的dUTP缺口末端标记以检测凋亡细胞，并进行免疫荧光染色以阐明Müller细胞中相关蛋白的表达和定位。采用单因素方差分析分析神经节细胞数量。
在0.6W/m²辐照度下，未观察到SD大鼠视网膜有损伤。在10.0W/m²辐照度下视网膜细胞受损，主要影响光感受器和视网膜色素上皮细胞，视网膜内核层的Müller细胞也受到影响。照射4小时后开始出现凋亡，并在24小时达到峰值。在1.5W/m²辐照度下，照射后12小时而非3小时观察到视网膜中度损伤。照射3天后，不同组间神经节细胞数量有显著差异。当照射时间为3小时时，在0.0、0.6、1.5和10.0W/m²不同辐照度下视网膜神经节细胞数量分别为41.42±0.17、40.58±0.50、40.92±0.32和22.83±0.79（F = 1305.86，P = 0.000）。当照射时间为12小时时，在0.0、0.6、1.5和10.0W/m²不同辐照度下视网膜神经节细胞数量分别为41.42±0.17、40.83±0.69、41.08±0.17和22.75±0.83（F = 1095.
