Iliev M, van der Zypen E, Fankhauser F
Anatomisches Institut der Universität Bern.
Klin Monbl Augenheilkd. 1995 May;206(5):376-9. doi: 10.1055/s-2008-1035468.
Obliteration of sclerostomy canals during the course of healing is of course undesirable, but before interference with the process can hope to be successful, a stepwise ultrastructural delineation of the course of events provoked by surgucal intervention is essential. In the current study, such an analysis is undertaken, and the changes in tissue morphology discerned correlated with observed modulations in IOP.
Two cw-Nd:YAG laser sclerostomies were created ab interno on one eye in each of ten rabbits; the unoperated fellow-eyes served as controls. IOP was monitored daily over a twelve-day period. Changes incurred within the canals and to collaterally damaged scleral tissue were analyzed at two-day intervals by light and electron microscopy.
The development of well-defined filtering blebs demonstrated the success of the procedure. IOP was significantly lowered during the entire course of the observation period, but after the fifth postoperative day, the blebs had disappeared. Within five days of surgical intervention, morphological analysis revealed the canal to be invaded by macrophages originating from both the iris root and episcleral tissue; these were actively engaged in the phagocytosis of intensely damaged collagen abutting on the lumen. A few days later, the lumen had become occluded by fibroblasts and a dense capillary network. The course of regeneration observed within scleral tissue which had undergone moderate thermal insult, suggests that collagen fibrils undergo a process of repolymerization.
Although the time course of repair is more rapid in rabbits than in humans, the data gleaned nonetheless yield valid information respecting the sequence of events involved in the scarification process. The loose nature of the tissue occluding the canal lumen apparently permits the percolation of fluid through it, thus accounting for the clinical discrepancy between a continuing decrease in IOP and the disappearance of a filtering bleb.
在愈合过程中巩膜造瘘管闭塞当然是不理想的，但在干预这一过程有望成功之前，对手术干预引发的一系列事件进行逐步的超微结构描绘至关重要。在本研究中，进行了这样的分析，并将所观察到的组织形态变化与眼压的调节相关联。
在10只兔子的每只眼睛内进行两次连续波Nd:YAG激光巩膜造瘘术；未手术的对侧眼作为对照。在12天的时间里每天监测眼压。每隔两天通过光学显微镜和电子显微镜分析造瘘管内以及受附带损伤的巩膜组织所发生的变化。
明确的滤过泡形成表明手术成功。在整个观察期内眼压显著降低，但术后第5天之后，滤过泡消失。手术干预后5天内，形态学分析显示造瘘管被源自虹膜根部和巩膜上组织的巨噬细胞侵入；这些巨噬细胞积极参与吞噬紧靠管腔的严重受损胶原蛋白。几天后，管腔被成纤维细胞和致密的毛细血管网阻塞。在遭受中度热损伤的巩膜组织内观察到的再生过程表明，胶原纤维经历了一个重新聚合的过程。
尽管兔子的修复时间进程比人类更快，但所收集的数据仍然提供了关于瘢痕形成过程中一系列事件的有效信息。阻塞管腔的组织质地疏松显然允许液体从中渗透，从而解释了眼压持续下降与滤过泡消失之间的临床差异。
