Comparative Change in Anterior Corneal Asphericity After FS-LASIK and SMILE

• Published in: Journal of refractive surgery (1995) Vol. 37; no. 3; pp. 158 - 165
• Main Authors: Ying, Jinglu, Zhang, Jun, Cai, Jianqiu, Pan, Fei
• Format: Journal Article
• Language: English
• Published: Thorofare Slack, Inc 01.03.2021; SLACK INCORPORATED
• Subjects: Comparative analysis; Cornea; Laboratories; Laser in situ keratomileusis; Lasers; Myopia; Patient outcomes; Patients; Photorefractive keratectomy; Topography; China
• ISSN: 1081-597X; 1938-2391
• DOI: 10.3928/1081597X-20210105-02

PURPOSE: To evaluate changes in anterior corneal asphericity (ΔQ) by calculating tangential radius ( r t ) after femtosecond laser–assisted in situ keratomileusis (FS-LASIK) and small incision lenticule extraction (SMILE). METHODS: Sirius corneal topography (Costruzione Strumenti Oftalmici) was used to evaluate 120 right eyes from patients with moderate and high myopia who had previously undergone FS-LASIK and SMILE. The preoperative and postoperative tangential radii obtained in reference to various semi-meridional regions and radii zones were compared. Variation in ΔQ values in semi-meridional regions across 360 degrees of the anterior surface after FS-LASIK and SMILE were compared. RESULTS: The tangential radii in the 1.2- and 1.8-mm radii zones were lower in patients who underwent SMILE compared to those who underwent FS-LASIK. The tangential radii in the 2.4- and 3-mm zones were higher in patients who underwent SMILE compared to those who underwent FS-LASIK. In both the moderate and high myopia groups, postoperative Q-values and ΔQ-values were lower in patients who had undergone SMILE than in patients who had undergone FS-LASIK. Postoperative Q-values and ΔQ-values were lower in the moderate myopia group than in the high myopia group for FS-LASIK and SMILE. The magnitude of variation in ΔQ as a function of semi-meridional region was lower in patients who had undergone SMILE than in patients who had undergone FS-LASIK. CONCLUSIONS: FS-LASIK and SMILE alter anterior corneal tangential radius and anterior corneal asphericity in patients with moderate or high myopia. SMILE is more effective than FS-LASIK in preserving normal anterior corneal asphericity. [ J Refract Surg . 2021;37(3):158–165.]