兔间接视神经损伤的组织病理学观察

Pathological study of indirect optic nerve injury in rabbits

目的 观察间接视神经损伤病理过程的规律以指导临床救治。 方法 日本大耳白兔 40只 ,按不同时相分为 8个组 ,左眼致伤 ,右眼为对照。建立兔间接视神经损伤模型后 ,分别于伤后 12h、1,3,7,15 ,30 ,6 0 ,90d处死动物取视神经 ,按常规方法制备光、电镜标本后 ,切片观察。 结果 伤后 12～ 2 4h神经软膜及神经组织水肿 ,毛细血管扩张、血管周围间隙增宽。鞘膜下血肿及神经实质内灶性出血 ,血管内皮细胞肿胀 ,管壁破裂和管腔闭塞。软膜下见神经挫伤性坏死区。 3d神经软膜及神经组织水肿减轻 ,髓鞘变性 ,轴突裸露 ,神经轴心出现梗死灶。7d变性加重 ,梗死区增大并见胶质细胞增生。 15d胶质增生加剧 ,崩解髓鞘开始清除 ,并见再生细小轴突出现。30d多数神经纤维髓鞘、轴突变性崩解及髓球形成 ,仅见少数基本正常的细小纤维呈岛状分布 ,有较多的再生轴突出现及胶质细胞增生。 6 0d变性崩解的髓鞘多数代谢完毕 ,再生轴突出现水肿 ,大量胶质细胞增生。 90d胶质细胞及胶质成分大量增生。 结论 视神经间接损伤存在原发性损伤 (早期挫伤性坏死 )和继发性损伤 (血管破裂、闭塞 ,神经轴心梗死区等微循环障碍 )。间接视神经损伤后可见明显的神经再生现象 ( 15～ 6 0d) ,且主要为细小纤维 。

Objective To observe the pathological course of indirect optic nerve injury and to direct clinical treatment. Methods After the indirect optic nerve injury was created in rabitts, the animals were sacrificed at interval of 12 hours,l,3,7,15,30,60 and 90 days after trauma. The optic nerve specimens were taken and fixed immediately after the sacrifice of animals. Then, the specimens were sliced and observed according to light and electron microscope routine procedures. Results At 12-24 hours interval, light microscope discovered edema of pialmatral and neural tissues, dilatation and congestion of capillaries. Through electron microscope, swelling of vascular endotheliocytes, rupture of vascular wall and occlusion of vascular lumen and neural contused necrotic were seen under part of subpial matral spaces. On the 3rd day, myelin sheath degeneration and nerve axons denuded and focal infarctions appeared in the nerve centre. On the 7th day, myelin sheath degeneration was exacerbated, the infarcted areas enlarged and the hyperplasis of gliocytes appeared. On the 15th day, regeneration of microaxons was observed. On the 30th day, most of nerve fibers showed myelinic degeneration, axonic denudation and formation of myelinic globules. Only a few basically normal micro-fibers were scattered in insulars. However, there were more regenerated axons and hyperplastic gliocytes. On the 60th day, most of the degenerated and denuded myelin sheath were completely metabolized; the regenerated axons became edematous, where as great amount of gliocytes became hyperplastic. On the 90th day, lots of hyperplastic gliocyte and collagen element were found, but the regenerated axons disappeared. Conclusions Pathological examination reveals that there are primary and secondary injuries in indirect optic nerve injury. Obvious nerve generation,especially the microfibers can be seen after indirect optic nerve injury.