外伤性视神经损伤后视神经及视网膜形态的动态观察

目的:了解外伤性视神经损伤后的病理变化、溃变特点与时相间的关系。方法:参照Allen脊髓损伤法,造成视神经眶尖段间接600gcm力冲击、挤压伤。伤后对视神经和视网膜行形态学动态观察。结果:①伤后48h,视神经轻度肿胀和空泡反应;1周时损伤处视神经出现溃变,神经胶质细胞增生,视网膜神经节细胞(retinalganglioncells,RGCs)形态改变不明显;2周时神经纤维轴束间空泡样改变,局灶性坏死,RGCs核固缩和细胞数量减少。术后3月,视神经损伤部位直径缩小,形成胶质疤痕,RGCs数量明显减少,核固缩细胞增多。②RGCs数量于术后48h、1周、2周、1月和3月分别比正常对照组低3.35%、13.23%、19.74%、23.20%、29.28%。③视网膜细胞在48h内出现凋亡。结论:本实验模型可造成明确的视神经和视网膜损伤,神经元的损伤程度从节细胞、中间神经元、感光细胞的次序依次递减。视网膜和视神经损伤的严重程度与时间呈相关性。RGCs数量在48h至1周时下降速率最快。

Morphological changes of optic nerve and retina after injury in the guinea pig

AIM: In order to understand the pathological changes, characteristic of degeneration in optic nerve and retina after strike of optic nerve. METHODS: According to methods of Allen's spinal injury, a 600gcm-strike power was put on the intraocular portion of the optic nerve and created a striking injury on optic nerve. After a survival interval of 48 h, 1 week, 2 weeks, 4 weeks, 3 months, the animal's optic nerves and retinas were collected and fixed for morphological examination. RESULTS: Forty-eight hours after nerve injuries, the optic nerves were slight enlargement and vacuolation. In 1 week, the optic nerve began to degenerate in injured part and the glia cell had proliferated, but the forms of retinal ganglion cells(RGCs) were normal. In 2 weeks, the vacuolation and focal necrosis were appeared between nerve fiber. The number of RGCs began to decrease. Condensed nuclei presented in the retina. In three month, the diameter of the optic nerve decreased in injury part and collo-scar was formed. The phenomenon mentioned above was more obviously. The internal nuclear neurons and outer nuclear neurons appeared rare. The thickness of retina decreased. The number of RGCs began to decrease in 48 hours and progressed thereafter. It decreased about 3.35%, 13.23%, 19.74%, 23.20%, 29.28% in 48 h, 1 week, 2 weeks, 1 month, 3 months compared with the number of normal RGCs. RGCs began to apoptosis in 48 h. CONCLUSION: The model in this experiment could make definite uncompleted optic nerve and retina injuries. The degree of neuron injuries decreased from RGC, internal nuclear neurons to outer nuclear neurons. The number of RGCs began to decrease in 48 hours, and most quickly periods from 48 hours to one week.