Ⅱ型胶原酶构建在体角膜扩张动物模型的可行性研究  

Feasibility of constructing keratectasia animal model using collagenase type Ⅱ

作　　者：乔静[1] 李海丽[1] 宋文静[1] 汤韵[1] 荣蓓[1] 杨松霖[1] 吴元[1] 晏晓明[1] 

机构地区：[1]北京大学第一医院眼科视觉损伤与修复教育部重点实验室,100034

出　　处：《中华实验眼科杂志》2017年第11期984-989,共6页Chinese Journal Of Experimental Ophthalmology

基　　金：国家自然科学基金项目（11372011）;非线性力学国家重点实验室开放基金资助项目

摘　　要：背景 圆锥角膜以角膜中央或旁中央进行性变薄膨出、高度散光或角膜瘢痕为临床特征，其发病机制和防治是研究热点，但目前尚无公认的圆锥角膜动物模型建立方法。圆锥角膜的解剖病理基础是角膜扩张，探讨角膜扩张的圆锥角膜动物模型的建立方法有助于对圆锥角膜的角膜生物力学变化进行研究。 目的 应用可视化角膜生物力学分析仪（Corvis ST）检测Ⅱ型胶原酶处理后角膜的生物力学性能，探讨利用Ⅱ型胶原酶构建在体角膜扩张模型的可行性。 方法 选取健康新西兰白兔10只，刮除兔眼角膜上皮后，将直径为8 mm的角膜环钻置于右眼角膜中央，滴入5 mg/ml Ⅱ型胶原酶（含质量分数15%右旋糖酐的PBS配制）溶液，浸泡角膜30 min制备角膜扩张模型，左眼以同样方法用含15%右旋糖酐的PBS浸泡角膜30 min作为对照。于造模前及造模后14 d，采用手持电子角膜曲率计和手持角膜超声测厚仪分别测定角膜平均曲率（Km）及中央角膜厚度（CCT），造模后14 d采用Corvis ST行在体角膜生物力学参数测定，过量麻醉法处死实验兔并收集角膜组织行组织病理学及透射电子显微镜检查。 结果 造模前，模型组和对照组兔Km值分别为（48.28±2.29）D和（48.82±1.63）D，CCT分别为（356.50±19.13）μm和（356.20±21.66）μm，差异均无统计学意义（均P〉0.05）。造模后14 d，模型组兔眼Km增加至（48.87±2.27）D，CCT减少至（340.40±19.84）μm，与对照组的（46.86±1.47）D和（367.80±23.38）μm比较，差异均有统计学意义（均P〈0.01）。造模后14 d，模型组兔角膜最大压陷深度平均值为（1.25±0.07）mm，明显大于对照组的（1.15±0.13）mm，差异有统计学意义（t＝2.65，P〈0.05），2个组间第1/第2压平时间、第1/第2压平角膜长度、第1/第2压平速度、最大压陷曲率半径和最大压陷时两屈膝峰间距的差异均�Background Keratoconus is a chronic and progressive non-inflammatory ectatic disorder characterized by corneal thinning and irregular corneal topography, and its pathgenesis is a hot topic.A suitable animal model of keratoconus is still lacking, which limits the progress of relevant research.Corneal ectasia is a main anatomical basis of keratoconus, so we assume that keratoconus model could be constructed by simulating corneal ectasia. Objective This study was to investigate the influence of collagenase type Ⅱ on biomechanical responses detected by corneal visualization Scheimpflug technology （Corvis ST） and the feasibility of construction of rabbit model of corneal ectasia using collagenase type Ⅱ. Methods This study protocol was approved by Ethic Committee of Peking University First Hospital and followed the Statement about experimental animal use and care from Association for Research in Vision and Ophthalmology （ARVO）. Keratectasia models were established in 10 right eyes of 10 New Zealand white rabbits by soaking 8 mm-diameter central cornea using collagenase type Ⅱ solution prepared by PBS solution containing 15% dextran （200 μl of 5 mg/ml） for 30 minutes after epithelial debridement, and only 200 μl PBS solution containing 15% dextran was used in the same way in the left eyes as controls.The average corneal curvature （Km） and central corneal thickness （CCT） were measured with hand-held electronic corneal curvature meter and corneal ultra-sonic pachymetry respectively before modeling and 14 days after modeling.Corneal biomechanical parameters and intraocular pressure were measured in vivo by using Corvis ST at day 14 after modeling.The rabbits were sacrificed at day 14 after modeling, and corneal sections were prepared for hematoxylin-eosin staining and transmission electron microscopic examination. Results There were no significant differences in Km and CCT between model group and control group before modeling （Km： [48.28±2.29]D vs.[48.82±1.63]D; CCT： [356.50±19.

关 键 词：生物力学 角膜/病理状态 Ⅱ型胶原酶 最大压陷深度 圆锥角膜 角膜扩张/化学诱导 兔 可视化角膜生物力学分析仪 

分 类 号：R-332[医药卫生] R772.2