title: Transition zone design and smoothing in custom laser-assisted subepithelial keratectomy.
abstract: OBJECTIVE
  To evaluate the results of custom laser-assisted subepithelial keratectomy (LASEK) with a specially designed transition zone and smoothing for the treatment of refractive errors.
  
  
  METHODS
  Department of Ophthalmology, Istituto Clinico Humanitas, Rozzano-Milan, Italy.
  
  
  METHODS
  This prospective study involved myopic eyes having refractive surgery with the butterfly LASEK technique and the Nidek EC-5000 excimer laser. The treatment was based on the surgeon's analysis of topographic and aberrometric data provided by Final Fit ablation software, which features the Custom Aspheric Transition Zone software algorithm. After the ablation, smoothing was performed to remove corneal microirregularities.
  
  
  RESULTS
  Fifty-five eyes of 38 patients were treated. The mean preoperative spherical equivalent (SE) refraction was -6.58 diopters (D) +/- 2.24 (SD) (range -12.13 to -1.75 D). At 1 year, the mean SE refraction was -0.26 +/- 0.79 D (range -4.00 to +0.75 D).
  
  
  CONCLUSIONS
  The surface ablation technique provided satisfactory results and took into account strategies to reduce unpredictability factors such as corneal biomechanical forces, haze induced by an irregular postoperative surface, and a high curvature gradient in the transition zone.
authors.affiliation: Department of Ophthalmology, Istituto Clinico Humanitas, Rozzano-Milan, Italy.
authors.forename: Paolo
authors.initials: P
authors.lastname: Vinciguerra
authors.forename: Fabrizio I
authors.initials: FI
authors.lastname: Camesasca
authors.forename: Ingrid M
authors.initials: IM
authors.lastname: Torres
mesh_terms: D000328:Adult; D001696:Biomechanical Phenomena; D003315:Cornea / Q000502:physiology*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D049008:Keratectomy, Subepithelial, Laser-Assisted / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D012029:Refraction, Ocular; D016896:Treatment Outcome; D014792:Visual Acuity