中文摘要：

目的观察猫视神经慢性受压后视网膜神经节细胞（R6Cs）的动态变化。方法30只成年家猫按随机数字表法等分为正常对照组、假手术组、压迫1周组、压迫2周组、压迫4周组和压迫8周组，每组5只。利用球囊植入法建立慢性视神经损伤模型。所有动物在术前2周用DiI逆行标记RGCs。取各组动物视网膜进行光镜、电镜观察，并存荧光显微镜下对RGCs进行计数。结果正常成年猫视网膜HE染色可见三层细胞核．各层间界限较为清楚，从玻璃体腔向巩膜依次为神经节细胞层、双极细胞层和感光细胞层；视神经慢性受压4周时视网膜变化仍不明显；受压8周时可见RGCs核明显稀疏，大而染色浅的细胞核基本消失，视网膜总厚度变薄，胶质细胞增生。电镜下正常猫RGCs核呈卵圆形、核大、核质均匀，有时可见核仁，胞浆占细胞比例小，但细胞器丰富；受压2周时视网膜无明碌改变：受压4周和8周时可见RGCs胞浆成分疏松、内质网扩张、线粒体肿胀、质膜下出现空泡、核膜皱缩内陷、胞浆空化、染色质边聚。正常组DiI逆行标记的RGCs的密度在406～527个／mm^2之间．平均为（465±381个／mm^2，中央区密度高于周边区；视神经受压后前4周RGCs数量无明显改变：受压8周时RGCs数量有显著下降，平均密度为（293±32）个／mm^2，下降约37％。结论视神经慢性受乐后RGCs将出现延迟的变性，为视神经受压后RGCs的保护提供了时机。

英文摘要：

Objective To observe dynamically the response of the retinal ganglion cells （RGCs） following chronic optic nerve compression in cats. Methods Thirty adult cats were randomly divided into 6 groups （n=5）： normal control group, sham operation group, 1-week compression group, 2-week compression group, 4-week compression group and 8-week compression group. The chronic optic nerve injury was produced by an inflatable balloon implanted under the optic chiasm. RGCs of all animals were labeled with DiI by retrograde tracing 2 weeks before operation. After each group animals were killed by perfusion, the retina were harvested to observe the pathological changes using the light microscope and electron microscope and the number of RGCs was counted under fluorescence microscope. Results There were three cell layers in normal HE stained retinas of cats with clear limits, named ganglion cell layer, bipolar cell layer and photoreceptor cell layer in sequence from vitreous body to sclera. By 4 weeks after optic nerve compression, there were no obvious pathological changes in the retinas, however, at 8 weeks the nuclei of the RGCs became markedly thin, with the larger almost disappearing, and the total thickness of the retinas reduced with the glial cells proliferating. Under electron microscopy, the RGCs of the normal cats had large ovate nuclei with homogeneous karyoplasms. The cytoplasm occupied only small space of the cells, but contained a great of cellular organelle. At 4 and 8 weeks after compression, it was found in the retinal ganglion cells that the components of cytoplasm reduced, the endoplasmic reticulum expanded, the mitochondria was swollen, the vacuole occurred under the plasma membrane, the membrane of nuclei was shrunk and the chromatin was marginated and condensed. The density of the DiI labeled RGCs in the normal group animals ranged from 406 to 527 cells/mm^2, with an average of （465±38） cells/mm^2 and higher density in the central area than in the peripheral one. The number of the RGCs was unch