摘要
目的研究激光周边虹膜切开术(laser peripheral iridoctomy,LPI)对患者眼内房水流动和角膜内皮细胞所受流体切应力的影响。方法参照文献中的人眼几何数据,在CAD软件中建立三维完整眼球几何模型,并结合有限元软件数值模拟LPI术后房水流动状态以及角膜内皮细胞所受切应力的变化,并对比LPI手术前后虹膜上不同激光开孔位置时角膜内表面切应力的数值结果。结果虹膜上激光孔的位置越靠近瞳孔中心,角膜受到的切应力越小。在激光孔离瞳孔轴距离分别为4.0、4.5、5.0、5.5 mm时,对应角膜内皮受到的最大切应力分别为16.5、25.8、57.0、179.8 m Pa。激光孔在3、6点方位时的切应力最大值比开孔在12点方位时的切应力最大值(56.95 m Pa)分别高出13.7%和4.2%。结论 LPI会改变患者眼内房水流动和角膜内皮细胞所受流体切应力。合适的开孔位置能降低角膜内皮细胞受到的切应力,减少LPI术后患者大泡角膜病变的风险。
Objective To study the influence of laser peripheral iridotomy（ LPI） on aqueous humor flow in eyes of patients and fluid shear stress exerted on the corneal endothelial cells. Methods A complete three-dimensional geometric eye model was established by CAD software with references to human eye geometric data from the literature. Numerical simulations on the flow conditions of aqueous humor and the shear stress exerted on corneal endothelial cells after LPI surgery were performed using finite element software. The simulation results of shear stresses at different positions of the laser hole in the iris before and after LPI surgery were compared. Results If the laser hole punched more closer to the pupil axis in iris,the shear stress exerted on corneal inner surface would be smaller. The maximum shear stress exerted on corneal endothelium was 16. 5,25. 8,57. 0,179. 8 m Pa when the distance between laser hole and the pupil axis was 4. 0,4. 5,5. 0,5. 5 mm,respectively. With laser hole at 3 and 6 o＇clock orientation,the maximum shear stress exerted on corneal inner surface was 13. 7% and4. 2% greater than that at 12 o＇clock position（ 56. 95 m Pa）. Conclusions LPI can influence the intraocular aqueous humor flow and shear stress exerted on corneal endothelial cells. The suitable position can decrease the shear stress exerted on corneal endothelial cells and reduce the risk of postoperative bullous keratopathy for patients after LPI surgery.
出处
《医用生物力学》
EI
CAS
CSCD
北大核心
2016年第1期33-39,共7页
Journal of Medical Biomechanics
基金
湖北省自然科学基金项目(2011CDB294)
中央高校基本科研业务费专项资金(2011JC010)
国家教育部回国人员科研启动基金
关键词
虹膜切开术
剪切力
角膜内皮
流体动力学
Laser iridotomy
Shear stress
Corneal endothelial
Hydrodynamics
