title: Advanced surface ablation for presbyopia using the Nidek EC-5000 laser.
abstract: OBJECTIVE
  To present 1 to 6-month follow-up results of laser in situ keratomileusis (LASIK) using multizone presbyopic advanced surface ablation (PASA) with a peripheral near zone.
  
  
  METHODS
  LASIK was performed on 28 eyes of 17 patients (10 men and 7 women; mean age 49.8 years with a range of 37 to 62 years). Eyes had primary or enhancement treatments with the Nidek EC-5000 excimer laser. Three techniques were used: 1) total transepithelial ablation, 2) surface ablation for far vision ametropia correction, and 3) concentric peripheral near zone presbyopia correction (technique developed by Dr. A. Telandro with a modified nomogram by Dr. R. Cantú for surface ablation). One surgeon (RC) performed all surgery.
  
  
  RESULTS
  We present the preoperative and postoperative measurements for far and near uncorrected visual acuity, total high order aberrations, spherical aberration (Z-12), asphericity Q index, eccentricity corneal shape factor, and total coma and trefoil aberrations. Increases occurred in negative spherical aberration, negative asphericity index, and positive eccentricity corneal shape factor.
  
  
  CONCLUSIONS
  Advanced surface ablation for presbyopia with a concentric peripheral near zone is a promising approach for surgical correction of presbyopia and potentially could be used with any advanced surface ablation procedure. Increases in negative spherical aberration and asphericity/ eccentricity indices seemed to increase the depth of focus of the eye, improving the near vision.
authors.affiliation: CVL, Laser Vision Correction, Puebla, Pue. Mexico. info@cvlaser.com
authors.forename: Roberto
authors.initials: R
authors.lastname: Cantú
authors.forename: Marco A
authors.initials: MA
authors.lastname: Rosales
authors.forename: Eduardo
authors.initials: E
authors.lastname: Tepichín
authors.forename: Andrée
authors.initials: A
authors.lastname: Curioca
authors.forename: Victor
authors.initials: V
authors.lastname: Montes
authors.forename: Julio
authors.initials: J
authors.lastname: Bonilla
mesh_terms: D000328:Adult; D003315:Cornea / Q000033:anatomy & histology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000295:instrumentation / Q000379:methods*; D008297:Male; D008875:Middle Aged; D011305:Presbyopia / Q000601:surgery*; D011446:Prospective Studies; D012030:Refractive Errors / Q000503:physiopathology; D014792:Visual Acuity / Q000502:physiology