兔眼冲击伤后早期视网膜超微结构改变

目的:通过对兔眼冲击波损伤后早期视网膜超微结构改变的动态观察,探讨眼冲击波损伤后视网膜结构改变及演变过程。方法:用激波管制成兔眼冲击波损伤动物模型,分别于伤后不同时点处死动物,摘取全眼球,取视飞纹下方后极部全层眼球壁,在透射电镜下观察其超微结构改变。结果:冲击波造成了一系列的视网膜结构改变。首先表现为视网膜视细胞结构损伤,如视细胞的外节出现微丝微管的断裂肿胀和结构紊乱、视盘肿胀和崩解、视细胞核肿胀碎裂;继而出现视网膜水平细胞和节细胞的反应性肿胀,线粒体等膜性细胞器明显肿胀,细胞间骨架破坏;随后视网膜内网状层肿胀,节细胞膜性细胞器明显肿胀,细胞间骨架破坏消失,细胞间结构异常、溶解消失。结论:眼冲击波损伤后视网膜视细胞的早期超微结构改变可能是冲击波的直接致伤效应所致,节细胞的结构紊乱可能是继发性改变,均是不可逆性视功能损害的病理改变基础。

Ultrastructural changes of the retina after ocular blast injury in rabbits

Objective: To investigate the ultrastructural pathogenesis of retina injury by observing the ultrastructural changes under the transmission electron microscope(TEM) after ocular blast injury in rabbits.Methods: Ocular blast injury models were set up in 20 rabbits by the bow wave produced with a bioshock tube.The rabbits were sacrificed at scheduled times after injury,their retinas obtained and their ultrastructural changes observed by TEM.Results: The axonal ultrastructural changes of the retina induced by blast were summarized as follows.The microfilaments and microtubules were swollen and distorted in the early stage,followed by reactive swelling of the ganglion cells.The swollen mitochondria and endoplasmic reticula focally accumulated and the cytoskeleton was destroyed.Finally the intraaxonal cellular structure disappeared and the axon disconnected.Conclusion: Ocular blast injury may cause retinal ultrastructural changes.The pathological changes of ganglion cells in the optic nerve may be associated with the direct effect of the blast and/or ischemia and are possibly important factors in the pathogenesis of vision disturbance.