活体猪眼行放射状视神经切开术后的组织病理学观察

Histopathological study after radial optic neurotomy in pigs′ eyes in vivo

目的观察活体猪眼行放射状视神经切开术(RON)后的病理改变过程,为临床RON安全性提供实验依据。方法健康小型猪共12只,其中8只双眼行RON后,分别于1、3、7、48d处死,每天各处死2只猪;2只猪一只眼行RON,另一只眼作正常对照;2只猪一只眼行RON,另一只眼行单纯玻璃体切除,于120d后处死。取出眼球后常规制作石蜡组织切片行苏木精伊红染色、Masson三色染色或Luxol坚固蓝染色,光学显微镜下对不同水平的视神经断面进行观察。结果所有眼球大血管壁未被破坏,球后视神经的软脑膜保持完整。手术后第1天可见创口形成,局部出血向周围及后方浸润,神经纤维髓鞘脱失所致的空泡样改变局限在创口内。手术后第3天时可见空泡样改变范围扩大。手术后第7天创口成纤维细胞密集,神经胶质细胞增生及分散的色素颗粒存在,浸润的炎性细胞以淋巴细胞和单核细胞为主。手术后第48天视盘创口胶原成分填充,切开深度未及的后方视神经局部神经胶质细胞密集,坚固蓝染色浅淡,边界清晰,其范围部分越过中线。手术后第120天创伤下方部位呈现局部视神经萎缩性改变。正常眼及单纯玻璃体切除眼切片光学显微镜观察未见病理改变。结论正常活体猪眼行RON后最终形成局部视神经萎缩,一定程度上手术本身是安全的。

Objective To explore the histopathological changes of the pigs′ eyes in vivo after radial optic neurotomy (RON), and provide the experimental foundation for the safety of RON. Methods A total of 12 healthy miniature pigs were used in the experiment, in whom 8 were executed at the 1~st , 3~rd , 7~th , and 48~th day respectively after underwent RON in both eyes, and 4 were executed at the 120~th day after underwent RON unilaterally (the other eye was as the control in 2 and underwent single vitrectomy in 2). All the enucleated eyes were cut in sections routinely and embeded in paraffin. The sections were stained by HE, Masson trichrome staining or Luxol fast blue staining and the different sections of optic nerve were observed by light microscope. Results No damages of the major vessel wall were found and the cerebral pia mater of orbital optic nerves kept integrated. At the 1~st day after the operation, the incisions came into being and local hemorrhages infiltrated into the circumambience and backside. The vacuole-like change induced by the demyelination of optic nerve fiber located at the incisions. At the 3~rd day, the vacuole-like changes widened. At the 7~th day, the fibroblasts aggregated at the incision, with hyperplastic neuroglia cells and dispersed pigmented granules. Lymphocytes and monocytes were the major infiltrated inflammatory cells. At the 48~th day, collagen filled in the incisions and aggregated neuroglia cells of the rear optic nerves behind the incision were found, which showed weak staining with obvious boundary which was somewhat beyond the midline of optic nerves. At the 120~th day, localized atrophy of optic nerve occurred under the incision. No abnormal pathological findings were found in the normal eyes and the eyes undergo vitrectomy. Conclusions Localized atrophy of optic nerves comes into being after the normal pig eyes in vivo underwent RON. The surgery is safe to some extent.