title: Influence of preoperative keratometry on refractive results after laser-assisted subepithelial keratectomy to correct myopia.
abstract: OBJECTIVE
  To study the relationship between preoperative keratometry and residual spherical equivalent (SE) after myopic laser-assisted subepithelial keratectomy (LASEK).
  
  
  METHODS
  Vissum Madrid, Madrid, Spain.
  
  
  METHODS
  This retrospective study comprised 1149 consecutive eyes that had LASEK to correct myopia. The relationship between preoperative keratometry and the 3-month postoperative SE was analyzed by linear regression. The same analysis was performed in the first decile (percentile 10) with the flattest keratometry readings, in the decile with the steepest readings, and in the quartiles with the lowest and highest preoperative myopia.
  
  
  RESULTS
  Preoperatively, the mean SE was -4.59 diopters (D) +/- 2.80 (SD) (range -0.25 to -13.00 D) and the mean keratometry, 44.20 +/- 1.60 D (range 39.00 to 49.00 D). Three months postoperatively, the mean SE was +0.05 +/- 0.50 D. There was a significant (P = .04), although weak (r2 = 0.003), correlation between the mean preoperative keratometry and residual SE. Linear regression showed a positive significant correlation within each decile. The correlation was weak in the decile with the flattest corneas (115 eyes) (r2 = 0.04, P = .04) and slightly stronger in the decile with the steepest corneas (115 eyes) (r2 = 0.1, P = .001) (ie, the steeper the cornea, the greater the overcorrection). There was a weak correlation in the group with higher preoperative myopia (r2 = 0.05, P = .0003) but no correlation in the lower myopia group (P = .3).
  
  
  CONCLUSIONS
  Preoperative corneal curvature did not seem to influence the spherical refractive outcomes after myopic LASEK.
authors.affiliation: Vissum Madrid, Madrid, Spain. lbenito@vissum.com
authors.forename: Laura
authors.initials: L
authors.lastname: de Benito-Llopis
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Teus
authors.forename: Jose M
authors.initials: JM
authors.lastname: Sánchez-Pina
authors.forename: Raquel
authors.initials: R
authors.lastname: Gil-Cazorla
mesh_terms: D001251:Astigmatism / Q000601:surgery; D006801:Humans; D049008:Keratectomy, Subepithelial, Laser-Assisted / Q000379:methods*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D009216:Myopia / Q000601:surgery*; D011184:Postoperative Period; D011300:Preoperative Care; D012029:Refraction, Ocular / Q000502:physiology*; D012189:Retrospective Studies; D014065:Tonometry, Ocular; D014792:Visual Acuity / Q000502:physiology