BACKGROUND To compare the changes in the anterior segment after femtosecond laser in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE) using a dual rotating Scheimpflug (DRS) analyzer (Galilei®; Ziemer Ophthalmology, Port, Switzerland). METHODS A total of 218 eyes of 109 patients who underwent FS-LASIK or SMILE for myopic correction were retrospectively studied. Ninety-eight eyes of 49 patients who underwent FS-LASIK were compared to 120 eyes of 60 patients treated with SMILE. A DRS analyzer was used for preoperative and 6-month postoperative anterior segment analyses. Measured variables included the central corneal thickness (CCT), anterior chamber depth (ACD), anterior and posterior keratometry (K), anterior and posterior best-fit sphere radius, and maximum posterior elevation (MPE). RESULTS After the procedure, the amount of CCT decrease was higher in the SMILE group than in the FS-LASIK group, but it was not statistically significant. The MPE was significantly increased after both procedures (p < 0.001 and p = 0.001 in the FS-LASIK and SMILE groups, respectively), with the amount of elevation being higher after FS-LASIK than after SMILE even though it was not statistically significant. And there was a significant change in the steep and average posterior K in the FS-LASIK group (p = 0.006 and 0.001, respectively), but not in the SMILE group. CONCLUSIONS Regarding changes in the MPE and posterior K, changes in the posterior corneal surface were greater after FS-LASIK than after SMILE. TRIAL REGISTRATION The trial registration number: KCT0003628. Date of registration: 15 March 2019.

中文翻译：

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使用双旋转Scheimpflug分析仪比较飞秒激光LASIK和SMILE后的前节变化。

背景技术为了比较飞秒激光原位角膜磨镶术（FS-LASIK）和小切口小孔镜摘除术（SMILE）使用双旋转Scheimpflug（DRS）分析仪（Galilei ;; Ziemer眼科，Port，瑞士）后的前段变化。方法回顾性分析109例行FS-LASIK或SMILE矫正近视的患者的218眼。将49例行FS-LASIK手术的患者的98眼与60例接受SMILE治疗的患者的120眼进行了比较。DRS分析仪用于术前和术后6个月的眼前节分析。测得的变量包括中央角膜厚度（CCT），前房深度（ACD），前后角膜曲率法（K），前后最佳拟合球半径和最大后仰角（MPE）。结果手术后，SMILE组的CCT降低量高于FS-LASIK组，但无统计学意义。两种手术后MPE均显着升高（FS-LASIK和SMILE组分别为p <0.001和p = 0.001），FS-LASIK后的抬高幅度高于SMILE后，即使在统计学上不显着。在FS-LASIK组中，陡峭的K和后平均K发生了显着变化（分别为p = 0.006和0.001），而在SMILE组中则没有。结论关于MPE和后K的变化，FS-LASIK术后角膜后表面的变化大于SMILE后。试用注册号：KCT0003628。注册日期：2019年3月15日。