Eye Center, Second Affiliated Hospital, College of Medicine, Zhejiang University, Hangzhou, China.
Curr Eye Res. 2021 Aug;46(8):1089-1095. doi: 10.1080/02713683.2021.1877310. Epub 2021 Jan 26.
To evaluate the agreement between the predicted and measured central corneal thickness (CCT) reduction after the small incision lenticule extraction (SMILE) surgery and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) surgery.
A total 165 patients were enrolled in this prospective study. Eighty patients with a mean spherical equivalent (SE) of -4.72 ± 1.80 Diopters (D) were treated with the FS-LASIK procedure and Eighty-five patients with a mean SE of -4.78 ± 1.63 D were treated with SMILE procedure. One eye for each patient was randomly selected and included for statistical analysis. Ultrasound pachymetry measurement and Scheimpflug camera corneal topography were performed preoperatively and 3 months postoperatively. The measured CCT reduction was calculated by comparing the preoperative examinations with postoperative examinations. Comparative statistics and linear regression analyses were performed.
The mean predicted CCT reduction was 95.02 ± 21.39 μm in FS-LASIK group and 103.49 ± 22.87 μm in SMILE group ( = .015). The prediction of laser platform was found to overestimate the measured CCT reduction for both FS-LASIK group (ultrasound 13.20 ± 9.34 μm) and SMILE group (ultrasound 13.12 ± 8.68 μm). The prediction of laser platform was found to systematically overestimate the measured CCT reduction in FS-LASIK group. In SMILE group, the difference between predicted and measured CCT reduction were found significantly related with the predicted CCT reduction ( < .001 for ultrasound; and = .004 for Pentacam).
A systematic overestimation of measured CCT reduction in FS-LASIK group did not influence the refractive precision of FS-LASIK. Due to the different biomechanical distributions in post-SMILE cornea, the measured CCT reduction was influenced as the changes in refractive correction. Nomogram adjustment for high myopic correction needs further research.
评估小切口透镜取出术（SMILE）和飞秒激光辅助原位角膜磨镶术（FS-LASIK）术后中央角膜厚度（CCT）减少的预测值与实测值之间的一致性。
本前瞻性研究纳入了 165 例患者。80 例等效球镜（SE）为-4.72±1.80 屈光度（D）的患者接受 FS-LASIK 治疗，85 例 SE 为-4.78±1.63 D 的患者接受 SMILE 治疗。每位患者的一只眼被随机选择并进行统计分析。术前和术后 3 个月进行超声角膜测厚和 Scheimpflug 角膜地形图检查。通过比较术前和术后检查来计算实测 CCT 减少量。进行了比较统计学和线性回归分析。
FS-LASIK 组平均预测 CCT 减少量为 95.02±21.39 μm，SMILE 组为 103.49±22.87 μm（ =.015）。发现激光平台的预测值高估了 FS-LASIK 组（超声 13.20±9.34 μm）和 SMILE 组（超声 13.12±8.68 μm）的实测 CCT 减少量。发现激光平台的预测值系统地高估了 FS-LASIK 组的实测 CCT 减少量。在 SMILE 组中，预测 CCT 减少量与实测 CCT 减少量之间的差异与预测 CCT 减少量显著相关（超声：<.001；Pentacam： =.004）。
FS-LASIK 组中实测 CCT 减少量的系统高估并未影响 FS-LASIK 的屈光精度。由于 SMILE 术后角膜的生物力学分布不同，屈光矫正的变化会影响实测 CCT 减少量。对于高度近视矫正，需要进一步研究列线图调整。
