Evaluation of the Difference between Predicted and Measured Central Corneal Thickness Reduction after SMILE and Femtosecond Laser-assisted LASIK for Myopia

• Published in: Current eye research 2021-08, Vol.46 (8), p.1089-1095
• Main Authors: Wu, Fang, Yin, Houfa, Yang, Yabo
• Format: Article
• Language: English
• Subjects: ablation depth; Adolescent; Adult; aspheric; Cornea - pathology; Cornea - surgery; Corneal Pachymetry; Corneal Stroma - surgery; Corneal Surgery, Laser - methods; Corneal Topography; Female; FS-LASIK; Humans; Keratomileusis, Laser In Situ - methods; Lasers, Excimer - therapeutic use; Lenticule thickness; Male; Myopia - physiopathology; Myopia - surgery; Organ Size; Predictive Value of Tests; Prospective Studies; Refraction, Ocular - physiology; SMILE; Visual Acuity - physiology; Young Adult
• ISSN: 0271-3683; 1460-2202
• DOI: 10.1080/02713683.2021.1877310

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 (P = .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 (P