title: Contralateral eye-to-eye comparison of wavefront-guided and wavefront-optimized photorefractive keratectomy: a randomized clinical trial.
abstract: OBJECTIVE
  Wavefront-guided (WFG) and wavefront-optimized (WFO) platforms for refractive surgery are designed for improved visual outcomes. It is unclear which treatment profile is superior for patients undergoing photorefractive keratectomy (PRK).
  
  
  OBJECTIVE
  To compare the safety, efficacy, predictability, stability, and higher-order aberrations in eyes undergoing WFG and WFO PRK.
  
  
  METHODS
  A prospective, randomized, fellow-eye-controlled clinical trial was conducted at the Byers Eye Institute at Stanford with enrollment between April 2009 and March 2011; 1 year of follow-up was included. Of 90 patients screened, 71 patients (142 eyes) with less than 12.00 diopters (D) of spherical myopia and less than 3.00 D of astigmatism were enrolled consecutively.
  
  
  METHODS
  One eye was randomized to undergo WFG PRK treatment (Visx CustomVue Star S4 IR excimer laser system; Abbott Medical Optics), and the fellow eye received WFO PRK treatment (WaveLight Allegretto Wave Eye-Q 400 Hz excimer laser system; Alcon Surgical).
  
  
  METHODS
  Data on the manifest refraction, uncorrected visual acuity, best-corrected visual acuity, 5% and 25% contrast best-corrected visual acuity, and higher-order aberrations were collected preoperatively and at the 1-, 3-, 6-, and 12-month follow-up visits.
  
  
  RESULTS
  Eyes undergoing both treatments had improved best-corrected visual acuity (WFG: mean, 0.05 [95% CI, 0.03-0.07]; WFO: mean, 0.04 [95% CI, 0.02-0.06]) and less sphere (WFG: mean, -4.79 [95% CI, -5.31 to -4.26]; WFO: mean, -4.61 [95% CI, -5.18 to -4.03]), cylinder (WFG: mean, 0.66 [95% CI, 0.49-0.82]; WFO: mean, 0.52 [95% CI, 0.35-0.69]), and spherical equivalents (WFG: mean, -4.45 [95% CI, -4.99 to -3.91]; WFO: mean, -4.34 [95% CI, -4.92 to -3.76]) (P < .001) but higher levels of spherical aberration (WFG: mean, -0.11 [95% CI, -0.15 to -0.06]; WFO: mean, -0.11 [95% CI, -0.14 to -0.07]) (P < .001) and higher-order root-mean-square aberrations (WFO: mean, -0.07 [95% CI, -0.12 to -0.02]; WFO: mean, -0.12 [95% CI, -0.17 to -0.70]) (P = .005 in WFG eyes and P < .001 in WFO eyes) at 12 months compared with preoperative measurements. A total of 93.0% of the eyes in the WFG group and 94.4% in the WFO had an uncorrected visual acuity of 20/20 or better at 12 months, with 56.3% in the WFG group and 43.7% in the WFO group gaining 1 or more lines of best-corrected visual acuity. The stability of the refractive correction was excellent for both groups.
  
  
  CONCLUSIONS
  A difference in uncorrected visual acuity or contrast acuity between eyes undergoing WFG or WFO treatment at 3 months and beyond could not be identified. This lack of difference suggests that both systems can be used to provide excellent improvement in vision for persons with myopia.
  
  
  BACKGROUND
  clinicaltrials.gov Identifier: NCT01135719.
authors.affiliation: Byers Eye Institute at Stanford, Palo Alto, California.
authors.forename: Lingmin
authors.initials: L
authors.lastname: He
authors.affiliation: Byers Eye Institute at Stanford, Palo Alto, California.
authors.forename: Edward E
authors.initials: EE
authors.lastname: Manche
mesh_terms: D057128:Aberrometry; D000328:Adult; D015350:Contrast Sensitivity / Q000502:physiology*; D057108:Corneal Wavefront Aberration / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D018903:Photorefractive Keratectomy / Q000379:methods*; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology*; D055815:Young Adult