Purpose This study analyzed the biomechanical responses of different corneal cap thicknesses after small incision lenticule extraction (SMILE). Methods Individual finite element models of myopic eyes were constructed based on the clinical data. Then, four types of corneal cap thicknesses after SMILE were included for each model. The biomechanical effects of material parameters and intraocular pressure on corneas with different cap thicknesses were analyzed. Results When the cap thickness increased, the vertex displacements of the anterior and posterior corneal surfaces decreased slightly. The corneal stress distributions demonstrated little change. Regarding wave-front aberrations caused by the displacements of the anterior surface, the absolute defocus value decreased slightly, but the magnitude of primary spherical aberration increased slightly. The horizontal coma increased, and the levels of other low-order and high-order aberrations were small and demonstrated little change. The corneal vertex displacement and wave-front aberration were significantly affected by elastic modulus and intraocular pressure, whereas the corneal stress distribution was greatly affected by intraocular pressure. There were obvious individual differences in the biomechanical responses of human eyes. Conclusions The biomechanical difference of different corneal cap thicknesses after SMILE was small. The effect of corneal cap thickness was significantly less than that resulting from material parameters and intraocular pressure. Translational Relevance Individual models were constructed based on the clinical data. The elastic modulus was controlled by programming to simulate its heterogeneous distribution in the actual human eye. The simulation was improved to bridge the gap between basic research and clinical care.

In this study, the wave-front aberrations of medium and high myopia with different CCT after SMILE were studied by the finite element method. Then, the various trend of wave-front aberrations with clinical significance was obtained. When CCT was the same, the wave-front aberrations of myopia with different diopters were different. When CCT increased, the variations of wave-front aberrations of myopia with different diopters were different. However, regardless of the degree of myopia, the variations of defocus and primary spherical aberration were the most obvious. The larger the CCT, the smaller the absolute values of defocus and primary spherical aberration.