非穿透性小梁切除术联合低浓度丝裂霉素C的实验研究

Experimental study of non-penetrating tra-beculectomy with low-dose mitomycin C

目的探讨应用低浓度丝裂霉素C的非穿透性小梁切除术后手术区的形态学变化及房水引流途径。方法新西兰白兔12只(24眼),随机分为实验组9只(18眼)和正常对照组3只(6眼)。实验组兔双眼行非穿透性小梁切除术,分别于术后1d、14d、1个月时随机选择3只兔,一眼前房注入辣根过氧化物酶(horse radish peroxidase,HRP),另一眼前房注入相对分子质量为70000四甲基罗丹明标记的葡聚糖(tetramethyl rhodamine-dextran,TMR-D)。60min后经颈动脉灌注固定,摘取眼球,冰冻切片,观察示踪剂的分布及手术区的形态学变化。正常对照组3只兔,双眼未行手术,示踪剂前房注入方法同前。结果实验组兔眼滤过泡及浅层巩膜瓣下的滤过腔于术后1d及14d时可见HRP强染色。术后14d时,滤过腔内未见明显纤维组织形成,滤过腔周围巩膜内有HRP散在染色。术后1个月时,滤过腔局限,少量HRP颗粒分布,滤过腔见纤维组织增生。正常对照组结膜下仅微弱HRP显色,巩膜内无HRP颗粒分布。实验组及正常对照组脉络膜均可见TMR-D红色荧光。结论非穿透性小梁切除术后房水引流途径涉及结膜下外滤过、巩膜内吸收及葡萄膜巩膜引流。

Objective To investigate the morphological findings and aqueous outflow pathways after non-penetrating trabeculectomy with low-dose mitomycin C.Methods Twelve rabbits were randomly divided into experimental group（9 rabbits,18 eyes） and control group（3 rabbits,6 eyes）.Non-penetrating trabeculectomy was performed on rabbits’ eyes of experimental group.At 1 day,14 days and 1 month after surgery,three rabbits were randomly chosen to receive intracameral injection of horseradish peroxidase（HRP） in one eye and tetramethyl rhodamine-dextran（TMR-D） in the other eye.After survival time of 60 minutes,the rabbits were fixed by carotid artery perfusion.The eyes were enucleated,and freeze sections were prepared to observe tracer’s distribution and the morphological changes of operative site.The same method of tracer’s intracameral injection was performed in control group,which was with 3 rabbits and no treatment was taken for both eyes.Results At 1 day and 14 days after surgery in experimental group,intensive HRP positive staining was seen in filtration bleb and the canal under the scleral flap.At 14 days after surgery,fibrous tissue was not found in the canal,HRP staining scattered in the sclera around filtration canal.At 1 month after surgery,HRP staining was weakened and fibrous tissue proliferation was found in the canal.In control group,feeble HRP staining was present under conjunctiva,but no HRP granules in sclera.Fluorescence was found in choroidal tissue of both experimental group and control group.Conclusion In this study,aqueous outflow pathways after non-penetrating trabeculectomy involve subconjunctival filtration,interscleral absorption and uveoscleral outflow.