应用翼点入路构建猫急性视神经损伤动物模型

Establishment of a cat model of acute optic nerve injury via pterional approach

目的构建猫急性视神经压迫损伤动物模型。方法成年健康猫36只,按损伤时间分为6 h、1 d、3 d、7 d、14 d 5个组,每组6只,正常对照组6只。模仿临床上翼点入路,显微手术暴露视神经,以无创血管夹夹持视神经20 s,行视觉诱发电位检查并研究急性视神经损伤前后视觉电生理方面的变化。以上动物按不同时间分组处死后,取视神经、视网膜标本,进行光镜电镜分析,研究损伤后视神经、视网膜的病理改变。结果视神经损伤后观察动物瞳孔较正常瞳孔变大,行闪光视觉诱发电位(FVEP)检查,P1波潜伏期延长,振幅明显降低。电镜下可见损伤后的视神经神经内膜、髓鞘、各板层、轴膜及轴索结构紊乱,视网膜神经节细胞数目减少。结论急性视神经损伤后视神经髓鞘、视网膜发生病理学方面的改变,视觉诱发电位也随之变化。采用翼点入路构建的动物模型可用于急性视神经损伤的研究。

Objective To establish an acute optic nerve injury model m cat. Methods Thirty cats were divided into five equal groups according to post-injury periods of 6 h, 1 d, 3 d, 7 d and 14 d. Six cats were used as the normal control. In sterile surgical conditions, pterional approach in human was performed with the aid of binocular microscope. After retraction of the brain, the optic nerve was exposed and squeezed for a period of 20 seconds near the optic foramen with a vascular clip. Before and after operation, the cats were tested by flash- visual evoked potential （FVEP） to establish normal and abnormal value. All the cats in six groups were killed under anesthesia, and the pathological changes of the optic nerve and the retinal ganglion cells （RGCs） after injury were observed. Results The FVEP manifested as the amplitude decreased and the latency prolonged. There were obvious electrophysiological changes after injury, accompanied by loosening of myelin sheath, derangement of endoneurium, axolemma and axis. The cell number of RGCs decreased. Conclusion There are significant uhrastructural changes in optic nerve myelin sheath and RGCs after acute injury accompanied by corresponding electrophysiological changes. This animal model via pterianal approach in human is stable for the investigation on the optic nerve injury.