Predictability of Central Corneal Stromal Reduction After SMILE and FS-LASIK for High Myopia Correction: A Prospective Randomized Contralateral Eye Study.

Abstract

PURPOSE:

To compare small incision lenticule extraction (SMILE) and femtosecond laser-assisted in situ keratomileusis (FS-LASIK) in terms of the predictability of central stromal thickness reduction in eyes with high myopia.

METHODS:

In this prospective, randomized contralateral eye trial, 42 patients received SMILE in one eye and FS-LASIK (using the Amaris 750S excimer laser [SCHWIND eye-tech-solutions]) in the fellow eye for the correction of high myopia (manifest refraction spherical equivalent: < -6.00 diopters). Spectral-domain optical coherence tomography was used to measure the central corneal and epithelial thickness. Pre-operative and postoperative values were compared to determine the amount of central stromal reduction achieved.

RESULTS:

At the 6-month follow-up visit, the amount of central stromal reduction was overestimated by 20.05 ± 5.92 µm in the SMILE group (P < .0001) and underestimated by 8.21 ± 8.14 µm in the FS-LASIK group (P < .0001). The mean actual central stromal reduction achieved with SMILE was significantly less than that achieved with FS-LASIK (10.10 ± 18.01 µm, range: 1.90 to 18.29 µm, P < .001). The discrepancy between the planned and achieved central corneal stromal reduction was not associated with refractive overcorrection or undercorrection in either the SMILE group or the FS-LASIK group (P = .9743 vs P = .0777).

CONCLUSIONS:

In patients with high myopia, the laser software platform may underestimate and overestimate the amount of actual corneal reduction in eyes treated with FS-LASIK and SMILE, respectively. SMILE required less corneal stroma compared to FS-LASIK in the studied cohort using the Amaris 750S excimer laser when correcting a similar spherical equivalent refraction. [J Refract Surg. 2022;38(2):90-97.].

• Authors: Yiqi Luo, Shengyu He, Pei Chen, Huan Yao, Anqi He, Yan Li, Jin Qiu, Min Lan, Jing Zhuang, Keming Yu
• Journal: Journal of refractive surgery (Thorofare, N.J. : 1995) (J Refract Surg) Vol. 38 Issue 2 Pg. 90-97 (Feb 2022) ISSN: 1081-597X [Print] United States
• PMID: 35156458 (Publication Type: Journal Article, Randomized Controlled Trial)

Topics

• Corneal Stroma (surgery)
• Humans
• Keratomileusis, Laser In Situ
• Lasers, Excimer (therapeutic use)
• Myopia (surgery)
• Prospective Studies
• Visual Acuity