Femtosecond laser small incision lenticule extraction (SMILE) with different residual stromal thicknesses (RST) is set to investigate its effect on corneal biomechanical properties of rabbits in vivo. In this study, 24 healthy adult Japanese rabbits were randomly divided into group A and B. The RST of group A was set 30% of the corneal central thickness (CCT), and the RST of group B was 50% of the CCT. The thickness of the corneal cap in both groups was set one third of CCT. Corneal visualization Scheimpflug technology (Corvis ST) and Pentacam three-dimensional anterior segment analyzer were used to determine corneal biomechanical and morphological parameters before surgery, and 1 week, 1 month and 3 months after surgery. Pearson correlation analysis was used to analyze factors affecting corneal biomechanical parameters after SMILE. The results showed that the corneal stiffness of group A was significantly higher than that of group B at 1 week and 1 month after surgery, and most biomechanical parameters returned to preoperative levels at 3 months postoperatively. The results of correlation analysis showed that postoperative CCT and RST were the main factors affecting corneal biomechanical parameters after SMILE. There was no significant difference in corneal posterior surface height (PE) between 3 months after surgery and before surgery in both two groups. It indicates that although the ability to resist deformation of cornea decreases in SMILE with thicker corneal cap and less RST, there is no tendency to keratoconus, which may be related to the preservation of more anterior stromal layer.
本文旨在探讨保留不同残余基质床厚度（RST）的飞秒激光小切口角膜基质透镜取出术（SMILE）对兔角膜在体生物力学性能的影响。本文选取24只健康成年日本大耳兔，随机分为A、B组，A组RST为角膜中央厚度（CCT）的30%，B组RST为CCT的50%，两组角膜帽厚度均设置为CCT的1/3，于术前以及术后1周、1月和3月分别行可视化角膜生物力学分析仪（Corvis ST）和Pentacam三维眼前节分析仪检查，从而获取角膜生物力学和形态学相关参数，并采用Pearson相关性分析研究SMILE术后角膜生物力学参数的影响因素。结果表明，A组术后1周及1月角膜硬度显著高于B组，术后3月时两组大多数生物力学参数均恢复至术前水平。相关性分析结果表明，术后CCT和RST是SMILE术后角膜生物力学参数的主要影响因素。术后3月与术前比较中，两组角膜后表面高度值（PE）均无显著差异。提示制备较厚角膜帽、保留较少RST的SMILE术在短期内虽然抵抗变形能力有所下降，但尚无圆锥角膜倾向，可能与保留较多前基质层有关。.
Keywords: Corneal biomechanical properties; Corneal morphology; Corvis ST; Femtosecond laser small incision lenticule extraction; Residual stromal thickness.