Finite Element Analysis of Corneal Deformation and Stress after LASIK
Xiuguo Chen1, Min Shen1, Yan Wang2,3, Di Wu2,3, Lin Zhang2,3
1Department of Mechanics, School of Mechanical Engineering, Tianjin University, Tianjin 300072, China; 2Tianjin Eye Hospital, Tianjin Eye Institute, Tianjin Key Laboratory of Ophthalmology and Visual Science, Tianjin 300020, China; 3Clinical Collge of Ophthalmology, Tianjin Medical University, Tianjin 300070, China
Abstract:Objective: We performed finite element analysis of corneal deformation and stress after laser in situ keratomileusis (LASIK) to study the influence of corrective diopter and preoperative corneal thickness on postoperative corneal biomechanical characteristics. Methods: The mechanical behavior of human corneal material was described through Gasser-Holzapfel-Ogden hyperelastic constitutive modeling. The preoperative and postoperative finite element models of corneal biomechanics were established, and the displacement differences of corneal posterior surface center after LASIK were calculated. The effects of different corrective diopters and preoperative corneal thicknesses on postoperative corneal deformation and Mises stress were analyzed. Results: The displacement difference of the corneal posterior surface center before and after LASIK surgery nonlinearly increased with the corrective diopter. The effect of preoperative corneal thickness on the displacement difference of the corneal posterior surface center was weaker for lower corrective diopters and stronger for higher ones. Conclusions: For higher diopters, corneal thickness had significant effect on postoperative corneal biomechanical stability. Due to the existence of the corneal flap, LASIK surgery is likely to cause increments of postoperative corneal stress.
陈修国, 沈珉, 王雁, 吴迪, 张琳. LASIK术后角膜变形和应力的有限元分析[J]. 中华眼视光学与视觉科学杂志, 2019, 21(2): 110-116.
Xiuguo Chen, Min Shen, Yan Wang, Di Wu, Lin Zhang. Finite Element Analysis of Corneal Deformation and Stress after LASIK. Chinese Journal of Optometry Ophthalmology and Visual science, 2019, 21(2): 110-116. DOI: 10.3760/cma.j.issn.1674-845X.2019.02.006
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