title: Clinical Outcomes After SMILE and Femtosecond Laser-Assisted LASIK for Myopia and Myopic Astigmatism: A Prospective Randomized Comparative Study.
abstract: OBJECTIVE
  To compare the clinical outcomes of small-incision lenticule extraction (SMILE) and femtosecond laser-assisted LASIK (FS-LASIK) for the correction of myopia and myopic astigmatism.
  
  
  METHODS
  In this prospective, randomized, comparative study, SMILE surgery was performed in 113 eyes with a mean spherical equivalent (MSE) of -5.22 ± 1.70 diopters (D) and FS-LASIK was performed in 84 eyes with an MSE of -5.18 ± 1.93 D. Contrast sensitivity and uncorrected and corrected distance visual acuities were measured preoperatively and 1 day, 1 week, 1, 3, and 6 months postoperatively. Higher-order aberrations were evaluated preoperatively and 6 months postoperatively.
  
  
  RESULTS
  At postoperative day 1, the uncorrected distance visual acuity in the FS-LASIK group was better (P < 0.05), whereas no statistically significant difference was found at 6 months postoperatively (P = 0.9). There was no significant difference in terms of logMAR corrected distance visual acuity and MSE during the 6 months of follow-up between the SMILE and FS-LASIK groups (all P > 0.05). The contrast sensitivity in the SMILE group was lower at 1 day and 1 week postoperatively (all P < 0.05). The spherical aberration at 6 mm diameter at 6 months postoperatively was lower (P < 0.05) in the SMILE group (0.12 ± 0.22 μm) than in the FS-LASIK group (0.28 ± 0.26 μm).
  
  
  CONCLUSIONS
  Both FS-LASIK and SMILE procedures achieved good visual outcomes in the correction of myopia and myopic astigmatism. SMILE had a lower induction rate of spherical aberration at 6 months postoperatively in the analysis of 6 mm diameter than that of FS-LASIK.
authors.affiliation: Refractive Surgery Center, State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China.
authors.forename: Manli
authors.initials: M
authors.lastname: Liu
authors.forename: Yile
authors.initials: Y
authors.lastname: Chen
authors.forename: Danyang
authors.initials: D
authors.lastname: Wang
authors.forename: Yugui
authors.initials: Y
authors.lastname: Zhou
authors.forename: Xiaoying
authors.initials: X
authors.lastname: Zhang
authors.forename: Jiexu
authors.initials: J
authors.lastname: He
authors.forename: Ting
authors.initials: T
authors.lastname: Zhang
authors.forename: Yuan
authors.initials: Y
authors.lastname: Sun
authors.forename: Quan
authors.initials: Q
authors.lastname: Liu
mesh_terms: D057128:Aberrometry; D000293:Adolescent; D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D015350:Contrast Sensitivity / Q000502:physiology; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000601:surgery*; D048988:Corneal Surgery, Laser; D057108:Corneal Wavefront Aberration / Q000503:physiopathology; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011379:Prognosis; D011446:Prospective Studies; D013524:Surgical Flaps; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult