title: Early clinical outcomes, including efficacy and endothelial cell loss, of refractive lenticule extraction using a 500 kHz femtosecond laser to correct myopia.
abstract: OBJECTIVE
  To assess the early clinical outcomes, including the efficacy and the endothelial cell loss, of femtosecond lenticule extraction using a 500 kHz femtosecond laser system to correct myopia.
  
  
  METHODS
  Department of Ophthalmology, Kitasato University, Kanagawa, Japan.
  
  
  METHODS
  Case series.
  
  
  METHODS
  This study evaluated eyes with a spherical equivalent of -4.26 diopters (D) ± 1.39 (SD) that had femtosecond lenticule extraction for myopia. Before surgery and 1 week and 1, 3, and 6 months after surgery, the safety, efficacy, predictability, stability, and adverse events of the surgery were assessed.
  
  
  RESULTS
  The study enrolled 38 eyes of 20 patients. The uncorrected distance visual acuity and corrected distance visual acuity 6 months after surgery were -0.14 ± 0.10 logMAR and -0.21 ± 0.09 logMAR, respectively. The safety index was 0.96 ± 0.19 and the efficacy index, 0.82 ± 0.17. At 6 months, all eyes were within ±0.50 D of the targeted correction. The mean manifest refraction change from 1 week to 6 months was 0.02 ± 0.28 D. The endothelial cell density was 2814 ± 199 cells/mm(2) preoperatively and 2762 ± 213 cells/mm(2) postoperatively; the change was not significant (P = .32, Wilcoxon signed-rank test). No vision-threatening complications occurred during the observation period.
  
  
  CONCLUSIONS
  Femtosecond lenticule extraction performed well in the correction of myopia. Neither significant endothelial cell loss nor serious complications occurred throughout the 6-month follow-up, suggesting femtosecond lenticule extraction is a viable surgical option to treat myopic eyes.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: Department of Ophthalmology, University of Kitasato School of Medicine, Kanagawa, Japan. kamiyak-tky@umin.ac.jp
authors.forename: Kazutaka
authors.initials: K
authors.lastname: Kamiya
authors.forename: Akihito
authors.initials: A
authors.lastname: Igarashi
authors.forename: Rie
authors.initials: R
authors.lastname: Ishii
authors.forename: Nobuyuki
authors.initials: N
authors.lastname: Sato
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nishimoto
authors.forename: Kimiya
authors.initials: K
authors.lastname: Shimizu
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery; D002452:Cell Count; D055954:Corneal Endothelial Cell Loss / Q000175:diagnosis / Q000209:etiology*; D063171:Corneal Pachymetry; D003319:Corneal Stroma / Q000601:surgery*; D004728:Endothelium, Corneal / Q000473:pathology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology; D053685:Laser Therapy / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011183:Postoperative Complications; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D013524:Surgical Flaps; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult