Safety evaluation after LASIK surgery based on the linear creep property:a finite element analysis  

作　　者：Ji-Xi Guo Xue-Feng Li Xin-Chao Wang Xin-Heng Zhao Yan Wang Li-Hua Fang 

机构地区：[1]Key Laboratory for Optoelectronic Information Perception and Instrumentation of Jiangxi Province,Nanchang Hangkong University,Nanchang 330063,Jiangxi Province,China [2]Tianjin Key Lab of Ophthalmology and Visual Science,Tianjin Eye Institute,Tianjin Eye Hospital,Nankai University Eye Institute,Nankai University,Clinical College of Ophthalmology,Tianjin Medical University,Tianjin 300000,China

出　　处：《International Journal of Ophthalmology(English edition)》2025年第5期889-896,共8页国际眼科杂志(英文版)

基　　金：Supported by National Natural Science Foundation of China(No.62165010);The National Key Research and Development Program of China(No.2022YFC2404502).

摘　　要：AIM:To investigate the effect of the percent tissue altered(PTA)on the safety after laser-assisted in situ keratomileusis(LASIK)based on linear creep characteristics.METHODS:The linear creep characteristics of the cornea were characterized by the generalized Kelvin-Voigt constitutive relationship with five parameters.Then,the displacement and stress distribution on the anterior and posterior surfaces of the cornea were analyzed by constructing the eye model with different PTA.RESULTS:When PTA was above 39%,the vertex displacements under physiological intraocular pressure(IOP,15 mm Hg)exceeded that of the preoperative glaucoma under average IOP.That is,an excessively high displacement value was found.In addition,with the increase of PTA,the central cornea was stretched thinner and more obviously due to IOP.When PTA was above 39%,the stress at the center of the anterior surface of the residual stroma was more than 20%larger than that of the normal human eye.The residual stroma was forced to stretch more severely due to excessive stress on the anterior surface.This resulted in deformation of the stroma and induced corneal ectasia.Meanwhile,the postoperative vertex displacement increased with the decrease in viscosity ratio.CONCLUSION:PTA less than 39%is the safe range for LASIK surgery.This study may provide a reliable numerical basis for postoperative corneal dilatation and the outcomes after refractive surgery.

关 键 词：laser-assisted in situ keratomileusis finite element percent tissue altered vertex displacement 

分 类 号：R779.63[医药卫生—眼科]