title: Objective and subjective preoperative refraction techniques for wavefront-optimized and wavefront-guided laser in situ keratomileusis.
abstract: OBJECTIVE
  To determine which of 3 methods for measuring preoperative refractive error yields the best refractive outcomes after wavefront-guided (Visx Star S4) or wavefront-optimized (WaveLight Allegretto Wave) excimer laser in situ keratomileusis (LASIK).
  
  
  METHODS
  Emory Eye Center and Emory Vision, Emory University, Atlanta, Georgia, USA.
  
  
  METHODS
  This retrospective analysis of LASIK, performed from June to December 2007, analyzed sphere, cylinder, and spherical equivalent (SE) refractions generated from 3 methods (manifest refraction, aberrometer autorefraction [CustomVue WaveScan], corneal analyzer autorefraction [Nidek ARK-10000 OPD]), actual programmed treatment, and absolute deviation from ideal treatment (deviation) for each technique.
  
  
  RESULTS
  In the wavefront-guided group (63 eyes, 33 patients), manifest refraction and aberrometer autorefraction generated similar deviation for sphere and SE; both were significantly better than corneal analyzer autorefraction (P= .02 and P= .03, respectively). Aberrometer autorefraction generated less cylinder deviation than the other methods (both P= .003). In the wavefront-optimized group (61 eyes, 36 patients), manifest refraction generated less deviation for sphere and SE than aberrometer autorefraction or corneal analyzer autorefraction (sphere: P= .005 and P= .009, respectively; SE: P= .005 and P= .002, respectively). Manifest refraction and aberrometer autorefraction cylinder generated similar deviation, while aberrometer autorefraction was less than corneal analyzer autorefraction (P= .041).
  
  
  CONCLUSIONS
  Overall, manifest refraction was most accurate in generating postoperative emmetropia with both laser treatments; however, aberrometer autorefraction produced the least cylinder deviation for wavefront-guided treatment. Corneal analyzer autorefraction produced the least accurate results with both lasers.
authors.affiliation: Emory Eye Center and Emory Vision, Emory University, Atlanta, Georgia, USA.
authors.forename: Claudia E
authors.initials: CE
authors.lastname: Perez-Straziota
authors.forename: J Bradley
authors.initials: JB
authors.lastname: Randleman
authors.forename: R Doyle
authors.initials: RD
authors.lastname: Stulting
mesh_terms: D000328:Adult; D003315:Cornea / Q000503:physiopathology* / Q000601:surgery; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology* / Q000601:surgery; D011300:Preoperative Care; D012029:Refraction, Ocular / Q000502:physiology*; D012189:Retrospective Studies; D013524:Surgical Flaps; D016896:Treatment Outcome; D014787:Vision Tests / Q000295:instrumentation; D014792:Visual Acuity / Q000502:physiology