title: Refractive lenticule extraction (ReLEx flex) and wavefront-optimized Femto-LASIK: comparison of contrast sensitivity and high-order aberrations at 1 year.
abstract: OBJECTIVE
  To compare 1-year results of the refractive lenticule extraction (ReLEx) flex technique performed as a commercial bilateral simultaneous procedure to a matched group of wavefront-optimized Femto-Lasik for correction of myopia and astigmatism with emphasis on contrast sensitivity and high-order aberrations (HOA).
  
  
  METHODS
  In this retrospective study 44 eyes of 22 patients with spherical equivalent (SE) of -5.13 D who underwent ReLEx were matched to 50 eyes of 25 patients with SE of -5.42 D treated by wavefront-optimized Femto-Lasik. We used Carl Zeiss Meditec (CZM) VisuMax(®) femtosecond laser system with a 200 kHz repetition rate. In addition, for Femto-LASIK, MEL 80 Excimer Laser (CZM) with aspheric ablation profiles was used for ablation.
  
  
  RESULTS
  At 1 year, the mean SE in the ReLEx group was -0.23 ± 0.35 D and in the Femto-LASIK group -0.15 ± 0.27 D. The mesopic contrast sensitivity of ReLEx treated eyes at 12 and 18 cpd improved from 1.49 and 0.99 to 1.54 and 1.1 respectively. In the Femto-LASIK group the numbers were pre-op 1.51 and 1.03, and after 1 year 1.54 and 1.06. The high-order aberrations (HOA) after ReLEx changed from 0.15 to 0.23 μm, and after Femto-LASIK from 0.175 to 0.320 μm (p = 0.0023).
  
  
  CONCLUSIONS
  At 1 year, wavefront-optimized Femto-LASIK produced similar refractive outcomes to ReLEx(®) flex with better, but non-significant accuracy. In contrast, ReLEx(®) flex showed significantly less induction of HOA and better mesopic mid-term contrast sensitivity then the wavefront-optimized Femto-LASIK.
authors.affiliation: Solomatin Eye Clinic, Riga, Latvia.
authors.forename: Jana
authors.initials: J
authors.lastname: Gertnere
authors.forename: Igor
authors.initials: I
authors.lastname: Solomatin
authors.forename: Walter
authors.initials: W
authors.lastname: Sekundo
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D015350:Contrast Sensitivity / Q000502:physiology*; D003315:Cornea / Q000503:physiopathology / Q000601:surgery*; D057108:Corneal Wavefront Aberration / Q000503:physiopathology*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D054023:Lasers, Semiconductor / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult