This study was to assess the impact on the cornea and eye blink activity of adapting rabbits to continuous lighting (CL) compared to a 14:10 light:dark cycle. Female New Zealand White rabbits (2 to 2.5 kg) were maintained under a light: dark (L:D) cycle or switched to continuous fluorescent lighting (CL) for an average of 17 +/- 2 days. Animal behaviour in their cages was manually recorded using an event marker and in vivo slitlamp biomicroscopy at 40× undertaken in mid-afternoon. Animals were then euthanized and the corneas prepared for scanning electron microscopy (SEM). From images taken at 500× from the central region of the corneas, the number of exfoliating (desquamating) cells and the relative number of different cells with light, medium or dark reflexes were assessed for the corneal epithelial surface, while the number of cells/unit area were assessed for both corneal epithelium and endothelium. Exposure to continuous lighting was associated with higher number of eye blink events (15.7 vs 8.2/15 min) and mild corneal surface alterations evident by biomicroscopy with higher numbers of intra-epithelial 'granules' (32 +/- 14 vs. 4 +/- 3/sq. mm). SEM revealed low numbers of exfoliating cells on the corneal epithelial surface in all CL-adapted animals, but not in L:D controls. Trends were observed for there to be slightly higher numbers of epithelial cells/unit area, higher numbers of small light reflex cells and lower numbers of larger dark reflex cells in CL animals. The corneal endothelium showed no obvious adverse effects in CL-adapted animals but the percentage of 'hexagonal' cells was slightly higher compared to L:D controls. The results indicate that even a short period of exposure of laboratory-raised rabbits to constant lighting can be associated with mild adverse effects on the corneal epithelial surface.

中文翻译：

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连续照明对笼养实验兔角膜的短期影响。

这项研究的目的是评估与14:10的光照：黑暗周期相比，适应连续光照（CL）的家兔对角膜和眨眼活动的影响。将雌性新西兰白兔（2至2.5千克）维持在光：暗（L：D）周期下，或切换到连续荧光灯（CL）进行平均17 +/- 2天。使用事件标记物手动记录其笼中动物的行为，并在午后进行40倍的体内裂隙灯生物显微镜检查。然后对动物实施安乐死，并准备将角膜用于扫描电子显微镜（SEM）。从角膜中央区域以500倍拍摄的图像中，评估了角膜上皮表面的脱落（脱皮）细胞数量以及具有亮，中或暗反射的不同细胞的相对数量，同时评估了角膜上皮和内皮细胞/单位面积的数量。暴露于连续光照下会导致眨眼次数增加（15.7 vs 8.2 / 15分钟），并且通过生物显微镜检查可见的角膜表面轻度改变与上皮内“颗粒”数量增加（32 +/- 14 vs. 4 + / -3 /平方毫米）。SEM显示，在所有适应CL的动物中，角膜上皮表面的脱落细胞数量很少，但L：D对照中没有。观察到趋势，在CL动物中，上皮细胞/单位面积的数量略高，小光反射细胞的数量较高，而较大的暗反射细胞的数量较少。在适应CL的动物中，角膜内皮没有明显的不良反应，但是与L：D对照相比，“六角形”细胞的百分比略高。