title: Vector analysis of 1-year astigmatic outcomes from a prospective, randomized, fellow eye comparison of wavefront-guided and wavefront-optimized LASIK in myopes.
abstract: OBJECTIVE
  To compare the astigmatic outcomes of LASIK with a single excimer laser platform using either wavefront-guided (WFG) or wavefront-optimized (WFO) modes.
  
  
  METHODS
  Sixty-eight eyes of 34 patients underwent LASIK for myopia with the Wavelight Allegretto Eye-Q 400-Hz laser platform (Alcon Laboratories, Inc., Hüenberg, Switzerland). One eye underwent WFG-LASIK and the contralateral eye underwent WFO-LASIK. Alpins vector analysis of astigmatism was performed using manifest refraction measured preoperatively and 12 months postoperatively and vertexed to the corneal plane. Eyes were stratified for subgroup analysis based on preoperative manifest astigmatism.
  
  
  RESULTS
  WFG-LASIK and WFO-LASIK were similar with regard to surgically induced astigmatism, difference vector, magnitude of error, correction index, flattening index, and index of success. The angle of error was 80% less in the WFG group compared to the WFO group (1.92° ± 0.67º vs 9.66° ± 3.7º, P = .04).
  
  
  CONCLUSIONS
  WFG-LASIK and WFO-LASIK using the Alcon WaveLight Allegretto Eye-Q 400-Hz excimer laser platform produce similar astigmatic results in myopic patients; however, the WFG mode may produce slightly more predictable astigmatic corrections.
authors.forename: Brian C
authors.initials: BC
authors.lastname: Toy
authors.forename: Caroline
authors.initials: C
authors.lastname: Yu
authors.forename: Edward E
authors.initials: EE
authors.lastname: Manche
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology*; D015350:Contrast Sensitivity / Q000502:physiology; D003315:Cornea / 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*; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology