管内段视神经损伤后视网膜的形态学改变

The Morphological Changes of Retina on Intracanalicular Optic Nerve Trauma

目的观察管内段视神经损伤后视网膜的病理变化,比较视神经管减压术和激素对管内段视神经损伤的作用。方法建立兔管内段视神经损伤的动物模型,利用免疫组织化学、图像分析等技术,观察神经损伤后,经视神经管减压术、地塞米松、视神经管减压术+地塞米松治疗14d后,视网膜的形态学改变及GAP-43的表达。结果视神经损伤1d后,RGCs平均记数轻度下降;损伤3,5,7d时,RGCs数分别为对照组的84.48%,72.23%,57.46%;14d时,节细胞仅有15.43%存活。损伤后3d,视网膜切片中可见GAP-43表达阳性的细胞;伤后5d阳性细胞增多;伤后7d阳性细胞数和积分光密度值达最高峰;伤后14d阳性细胞数下降。经手术减压、激素治疗、激素+手术治疗后,RGCs存活率分别为36.01%,32.78%,56.98%.结论管内段视神经损伤后RGCs出现渐进性退变,数量逐渐减少;视神经管减压术和激素对管内段视神经损伤有一定的治疗作用,其疗效明显优于采用单一方法。

Objective To observe the pathological change of retina and the treatment of optic canal decompression and dexamethasone on the intracanalicular optic nerve injury. Methods The experimental model of optic nerve injury at the canalicular segment was produced in healthy adult rabbits. The pathological change and the expression of the growth associated protein-43 （ GAP-43 ） of retina were observed by immunohistochemistry and image analysis ＇after these rabbits are treated 14 days by means of optic nerve decompression ,dexamethasone ,optic nerve decompression and dexamethasone. Results The number of retinal ganglion cells was obviously decreased except on the 1st day（ P 〉 0.05） ,the respective survival rate at interval 3,5,7d was 84.48% ,72.23% ,57.46%. On the 14th day, the retina appeared to be atrophy and thin, each layer boundary become unclear, the number of retina ganglion cells had 15.43% survival rate. The expression of GAP-43 began to be observed on the 3rd day,located in RGCs layers,the cell body was dyed to brown,the nucelus were colorless. And then gradually increased, attained the highest level on the 7th day, on the 14th day still observed its expression. The layers of retina of treating groups were clearer than the control group, and the survival rate of RGCs by decompression, dexamethasone, decompression and dexametha- zone was 36.01% ,32.78% ,56.98% respectively. Conclusions The number of RGCs decreased, and structures was changed after intra- canalicular optic nerve injury. Optic nerve decompression and corticosteroid are benefit to intracanalicular optic nerve injury, but there is no significant difference between them. The effective rate in rabbits received the treatment of optic nerve canal decompression and corticosteroid simultaneously is significantly higher than those received the single treatment of optic nerve canal decompression or cortieosteroid.