title: Refractive lenticule extraction: transition and comparison of 3 surgical techniques.
abstract: OBJECTIVE
  To describe the transition and outcomes of 3 refractive lenticule extraction (ReLEx) techniques: femtosecond lenticule extraction (FLEx), small-incision lenticule extraction (SMILE), and pseudo small-incision lenticule extraction.
  
  
  METHODS
  Singapore National Eye Center, Singapore.
  
  
  METHODS
  Prospective comparative case series.
  
  
  METHODS
  Refractive lenticule extraction was performed between March 1, 2010, and November 1, 2012, using the Visumax 500 kHz femtosecond laser system. The main outcome measures were the refractive efficacy, predictability, and safety over 12 months.
  
  
  RESULTS
  The study enrolled 88 eyes. All 3 refractive lenticule extraction techniques yielded good refractive outcomes and stability over 12 months. Three months postoperatively, the mean overall efficacy index of refractive lenticule extraction was 0.89±0.22 (SD), with 95.5% of eyes attaining an uncorrected distance visual acuity (UDVA) of better than 20/40 and 60.2% of better than 20/20. Of all eyes, 95.5% were within ±1.00 diopter (D) and 78.4% within ±0.50 D of the attempted correction. The mean overall safety index was 1.06±0.17. At 3 months, all small-incision lenticule extraction eyes and 96.7% of pseudo small-incision lenticule extraction eyes had a UDVA of 20/40 or better, while femtosecond lenticule extraction eyes had a lower efficacy index (87.0%). However, efficacy was comparable in all 3 groups by 12 months (mean 0.87±0.04 [standard error of the mean]; P=1.00).
  
  
  CONCLUSIONS
  The efficacy, safety, and predictability profiles of the 3 refractive lenticule extraction techniques were good over a 12-month follow-up.
  
  
  BACKGROUND
  No author has a financial or proprietary interest in any material or method mentioned.
authors.affiliation: From the Singapore National Eye Centre (Ang, Mehta, Chan, Koh, Tan), the Singapore Eye Research Institute (Ang, Mehta, Htoon, Tan), Duke-NUS Graduate Medical School (Mehta, Htoon), and the National University Health System (Tan), Singapore.
authors.forename: Marcus
authors.initials: M
authors.lastname: Ang
authors.affiliation: From the Singapore National Eye Centre (Ang, Mehta, Chan, Koh, Tan), the Singapore Eye Research Institute (Ang, Mehta, Htoon, Tan), Duke-NUS Graduate Medical School (Mehta, Htoon), and the National University Health System (Tan), Singapore.
authors.forename: Jodhbir S
authors.initials: JS
authors.lastname: Mehta
authors.affiliation: From the Singapore National Eye Centre (Ang, Mehta, Chan, Koh, Tan), the Singapore Eye Research Institute (Ang, Mehta, Htoon, Tan), Duke-NUS Graduate Medical School (Mehta, Htoon), and the National University Health System (Tan), Singapore.
authors.forename: Cordelia
authors.initials: C
authors.lastname: Chan
authors.affiliation: From the Singapore National Eye Centre (Ang, Mehta, Chan, Koh, Tan), the Singapore Eye Research Institute (Ang, Mehta, Htoon, Tan), Duke-NUS Graduate Medical School (Mehta, Htoon), and the National University Health System (Tan), Singapore.
authors.forename: Hla M
authors.initials: HM
authors.lastname: Htoon
authors.affiliation: From the Singapore National Eye Centre (Ang, Mehta, Chan, Koh, Tan), the Singapore Eye Research Institute (Ang, Mehta, Htoon, Tan), Duke-NUS Graduate Medical School (Mehta, Htoon), and the National University Health System (Tan), Singapore.
authors.forename: Jane C W
authors.initials: JC
authors.lastname: Koh
authors.affiliation: From the Singapore National Eye Centre (Ang, Mehta, Chan, Koh, Tan), the Singapore Eye Research Institute (Ang, Mehta, Htoon, Tan), Duke-NUS Graduate Medical School (Mehta, Htoon), and the National University Health System (Tan), Singapore. Electronic address: donald.tan.t.h@snec.com.sg.
authors.forename: Donald T
authors.initials: DT
authors.lastname: Tan
mesh_terms: D000328:Adult; D003319:Corneal Stroma / Q000601:surgery*; D048988:Corneal Surgery, Laser / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007431:Intraoperative Complications; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011183:Postoperative Complications; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D013524:Surgical Flaps; D014792:Visual Acuity / Q000502:physiology