title: Evaluation of the difference between intended and measured ablation and its impact on refractive outcomes of the wavefront optimize profile and the S001 Wellington nomogram in myopic spherocylindrical corrections.
abstract: BACKGROUND
  To evaluate the level of agreement between intended and measured ablation of the wavefront optimize profile corrected by the Wellington nomogram in myopic spherocylindrical corrections and assess its impact on refractive outcomes.
  
  
  METHODS
  Prospective, university-institute setting.
  
  
  METHODS
  Eighty-six participants (86 eyes for photorefractive keratectomy group) and 86 participants (86 eyes for laser in situ keratomileusis group) recruited in a consecutive-if -eligible basis.
  
  
  METHODS
  Differences between intended and measured ablation were evaluated with Scheimpflug camera. Refractive outcomes were evaluated by means of postoperative spherical equivalent, postoperative defocus equivalent, contrast sensitivity, correction index, difference vector and index of success.
  
  
  METHODS
  Correlation of visual outcomes with intended ablation.
  
  
  RESULTS
  Both groups demonstrated significant over-ablations (16.7±8.5, P<0.001 & 11.8±18.5, P<0.001, respectively). Intended ablation was the primary determinant of the measured difference (r-square 0.769 & 0.765, respectively). Photorefractive keratectomy corrections over 100µ had significant impact on postoperative spherical equivalent, postoperative defocus equivalent, correction index, difference vector and index of success (P=0.044, P=0.05, P=0.019, P=0.016, P=0.006, respectively), but laser in situ keratomileusis corrections over 100µ had significant impact only on postoperative defocus equivalent, difference vector and index of success (P=0.04, P=0.05).
  
  
  CONCLUSIONS
  The results suggest that the wavefront optimize profile seems to over-ablate corneal tissue both in photorefractive keratectomy and laser in situ keratomileusis. Over-ablation exerts significant impact on refractive outcomes only in high spherocylindrical corrections.
authors: Department of Ophthalmology, University Hospital of Alexandroupolis, Greece. labiris@usa.net
authors: Georgios
authors: G
authors: Labiris
authors: Haris
authors: H
authors: Sideroudi
authors: Athanassios
authors: A
authors: Giarmoukakis
authors: Stavrenia
authors: S
authors: Koukoula
authors: Georgios
authors: G
authors: Pagonis
authors: Vassilios P
authors: VP
authors: Kozobolis
mesh_terms: D000293:Adolescent; D000328:Adult; D003319:Corneal Stroma / Q000601:surgery*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D049451:Nomograms; D018903:Photorefractive Keratectomy; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology*; D013524:Surgical Flaps; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult