目的 建立大鼠非动脉炎性前部缺血性视神经病变(NAION)模型,定性、定量评价视网膜、视神经的损伤情况.方法 采用随机数字表法将健康雄性Sprague-Dawley大鼠47只分为正常对照组、单纯激光组、NAION模型组,各有13、11、23只大鼠.取右眼为实验眼.NAION模型组采用孟加拉玫瑰红联合激光光动力方法建立模型.单纯激光组大鼠采用与NAION模型组相同的激光参数照射视盘,不注射光敏剂.正常对照组大鼠不作干预.建模后12 h及1、3、7、28 d,利用直接检眼镜观察大鼠视网膜及视盘情况.使用苏木精伊红染色及透射电子显微镜定性评价NAION模型视盘、视网膜组织形态改变.利用经上丘荧光金逆行标记技术及荧光显微镜照相,定量评价NAION大鼠视网膜神经节细胞(RGC)密度及存活率.结果 NAION模型组大鼠于建模后3 d视盘水肿明显,视神经轴突水肿、部分髓鞘解体;建模后7 d,视盘水肿基本消退;建模后28 d,视神经萎缩,大量轴突消失伴明显胶质化改变,RGC明显减少.正常对照组、单纯激光组大鼠无上述视盘及视网膜形态改变.NAION模型组与正常对照组、单纯激光组大鼠右眼RGC密度比较,差异均有统计学意义(t=-14.142、-14.088,P=0.000、0.000).NAION模型组与正常对照组、单纯激光组大鼠RGC存活率比较,差异均有统计学意义(t=-17.048、-16.667,P=0.000、0.000).正常对照组与单纯激光组大鼠RGC密度、存活率比较,差异无统计学意义(t=0.050、0.348,P=0.961、0.731).结论 孟加拉玫瑰红联合激光光动力方法可引起大鼠视神经轴突损伤及RGC死亡,成功建立NAION模型.%Objective To establish and evaluate a rat model of nonarteritic anterior ischemic optic neuropathy (NAION).Methods The rats were randomly divided into control group (n=13), sham laser group (n=11) and NAION group (n=23). The right eye was set as the experimental eye. NAION model was induced by directly illuminating the optic nerve (ON) of the right eye with 532 nm green laser, after intravenous infusion with the photosensitizing agent Rose Bengal. Sham laser treatment consisted of illuminating the ON region with 532 nm laser without Rose Bengal injection. Rats in control group underwent no intervention. The appearance of optic disc was observed with funduscope at 12 hours, 1, 3, 7, 28 days post-illumination. The histologic changes in the retina and ON of the NAION model were evaluated qualitatively with hematoxylin and eosin (HE) staining and transmission electron microscopy. The retrograde-labeled retinal ganglion cells (RGC) were counted on photographs taken from retinal flat mounts in a masked fashion.Results The optic disc in NAION eyes were swollen 3 days after photodynamic treatment. HE-stained longitudinal ON sections of NAION revealed vacuolar degeneration on day 3 after induction. Besides, ultrastructural study showed axonal edema and collapsed sheaths in the ischemic optic nerve at the same time point after modeling. ON edema resolved 7 days after induction. The final results revealed optic disc atrophy, extensive axonal loss, severe glial scar, and RGC death in large numbers 4 weeks after modeling. There were no aforementioned manifestations in control and sham laser group. The RGC density of the right eyes was statistically significantly lower in NAION group than that in control group and in sham laser group (t=?14.142, ?14.088;P=0.000, 0.000). The survival rate of RGC was statistically significantly lower in NAION group than in control group and in sham laser group (t=?17.048, ?16.667;P=0.000, 0.000). There was no difference of RGC density and survival rate of RGC between control and sham laser group (t=0.050, 0.348;P=0.961, 0.731).Conclusion A rat model of NAION was established successfully by photodynamic treatments with Rose Bengal, which induce optic nerve damage and RGC death.
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