小梁切除术后薄壁滤过泡的临床及病理分析

Clinical and histopathologic analysis of thin filtering bleb after trabeculectomy

目的分析小梁切除术后薄壁滤过泡患者的临床和病理改变,探讨薄壁滤过泡患者低眼压等相关并发症的发生机制。设计回顾性病例系列。研究对象薄壁滤过泡相关并发症患者30例。方法收集1999年1月至2008年9月在中山眼科中心因小粱切除术后薄壁滤过泡相关并发症须行滤过泡加固术的青光眼患者30例。记录患者的眼压及眼部薄壁滤过泡相关并发症的情况,分析患者小梁切除术中丝裂霉素C(MMC)的使用情况。。对其中7例患者的滤过泡壁边缘组织行组织病理检查。主要指标眼压、并发症情况、MMC使用情况,滤过泡病理结果。结果患者行滤过泡加固术时距小梁切除术时间为5个月～9年(平均49.0±33.3个月)。患眼眼压2.7～11.0 mmHg,平均(4.40±4.49)mmHg。低眼压21例(70%),滤过泡渗漏18例(60%),浅前房2例(6.7%),低眼压性黄斑水肿7例(23.3%),巨大薄壁滤过泡5例(16.7%),滤过泡赘生至角膜上皮下4例(133%),滤过泡炎5例(16.7%),眼内炎2例(6.7%)。所有患者均有小梁切除术中MMC使用史。使用较高浓度MMC(≥0.286 mg/ml)的患者占53.33%。病理结果显示,滤过泡结膜上皮变性,厚薄不均,局部萎缩变薄甚至上皮缺如。上皮下纤维结缔组织变性、增生或结膜下疏松、囊腔样的纤维组织;结膜上皮内生,上皮下形成囊样腔隙。结论小梁切除术后薄壁滤过泡可引起一系列眼部严重并发症,MMC造成的局部结膜上皮变薄或缺如是其低眼压的主要原因;滤过泡结膜下组织结构的破坏及上皮内生在其低眼压的发病中起一定作用。

Objective To analyze the clinical and histopathologic changes of thin filtering bleb and investigate the pathogenesis of hypotony and other related complications after trabeculectomy. Design Retrospective case series. Participants Thirty consecutive patients admitted to Zhongshan Ophthalmic Center for surgical revision of thin filtering bleb because of thin-bleb-related complications from January, 1999 to September, 2008. Methods The intraocular pressure and thin-bleb-related complications of the patients were recorded. The different mitomycin C （MMC） doses applied in trabeculectomy were analyzed. Marginal samples of the filtering bleb wall were taken for histopathologic examinations in seven patients with hypotony during surgical revision of the bleb. Main Outcome Measures Intraocular pressure, thin-bleb-related complications, MMC doses, histopathologic results of the filtering bleb. Results The time of surgical revision of bleb from trabeculectomy was 5 months to 9 years, average （49.0±33.3） months. The intraocular pressure before surgical bleb revision was 2.7-11.0 mmHg, average （4.40±4.49） mmHg. The thin-bleb-related complications included： hypotony （21 cases, 70%）, bleb leaking （18 cases, 60%）, shallow anterior chamber （2 cases, 6.7%）, hypotony-induced macular edema （7 cases, 23.3%）, huge thin bleb（5 cases, 16.7%）, overhanging filtering bleb （4 cases, 13.3%）, blebitis（5 cases, 16.7%） and endophthalmitis （2 cases, 6.7%）. All patients had a history of MMC application in the trabeculectomy procedure, and 53.33% used high-dose MMC （≥0.286 mg/ml）.The histopathnlogic examinations disclosed degeneration, thinning, even local interruption of the bleb conjunctival epithelium. The subjacent connective tissue was fibroblastic and degenerated. Subconjunctival loose connective tissue containing clear spaces and conjunctival epithelium ingrow to form cyst-like structure were found. Conclusions The thin filtering bleb after trabeculectomy may cause many serious ocular complications. Local thinning and interruption of the conjunctival epithelium on the bleb due to MMC application （especially high-dose MMC） might be the main cause of hypotony. And disorganization of the subconjunctival connective tissue and epitheliam ingrowth might be also involved in the pathogenesis of hypotony.