title: Topographically guided LASIK for myopia using the Nidek CXII customized aspheric treatment zone (CATz).
abstract: OBJECTIVE
  To assess the efficacy, predictability, and safety of topography-guided laser in situ keratomileusis (LASIK) for the surgical correction of low to moderate myopia with astigmatism using the Nidek CXIII excimer laser equipped with the customized aspheric treatment zone (CATz) algorithm.
  
  
  METHODS
  In a multicenter US Food and Drug Administration study of topography-guided LASIK, 4 centers enrolled 135 eyes with manifest refraction sphere that ranged from -0.50 to -7.00 D (mean, -3.57 +/- 1.45) with up to -4.00 D of astigmatism (mean, -1.02 +/- 0.64 D). The intended outcome was plano in all eyes. Refractive outcomes and higher-order aberrations were analyzed preoperatively and postoperatively. Patient satisfaction was assessed using both the validated Refractive Status and Vision Profile (RSVP) questionnaire and a questionnaire designed for this study. Six-month postoperative outcomes are reported here.
  
  
  RESULTS
  By 6 months postoperatively, the manifest refraction spherical equivalent (MRSE) for all eyes was -0.09 +/- 0.31 D. Six months postoperatively, 116 of 131 eyes (88.55%) had an uncorrected visual acuity of 20/20 or better, and 122 of 131 eyes (93.13%) had a MRSE within +/-0.50 D. Distance best spectacle-corrected visual acuity (BSCVA) increased by 2 or more lines in 21 of 131 eyes (19.01%), and no eyes lost 2 lines or more of BSCVA. The total ocular higher-order aberrations root-mean-square increased by 0.04 microm postoperatively. Patients reported significantly fewer night driving and glare and halo symptoms postoperatively than preoperatively.
  
  
  CONCLUSIONS
  Nidek CXIII CATz treatment of myopia with astigmatism is safe, efficacious, and predictable, and it reduces patient symptoms associated with night driving and glare and halo symptoms.
authors.affiliation: Department of Ophthalmology, Emory University, Atlanta, Georgia, USA.
authors.forename: George
authors.initials: G
authors.lastname: Waring
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Dougherty
authors.forename: Arturo
authors.initials: A
authors.lastname: Chayet
authors.forename: Jeffery
authors.initials: J
authors.lastname: Fischer
authors.forename: Barbara
authors.initials: B
authors.lastname: Fant
authors.forename: Gary
authors.initials: G
authors.lastname: Stevens
authors.forename: Harkaran S
authors.initials: HS
authors.lastname: Bains
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000150:complications / Q000601:surgery; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000295:instrumentation* / Q000379:methods*; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D012031:Refractometry; D012449:Safety; D013997:Time Factors; D016896:Treatment Outcome; D014481:United States; D014486:United States Food and Drug Administration