title: Topography-guided treatment of irregular astigmatism with the wavelight excimer laser.
abstract: OBJECTIVE
  To evaluate the feasibility, safety, and predictability of correcting high irregular astigmatism in symptomatic eyes with the use of topography-guided photoablation.
  
  
  METHODS
  In a prospective, non-comparative case series, 16 consecutive symptomatic eyes of 11 patients with small hyperopic and myopic excimer laser optical zones, decentered and irregular ablation after corneal graft, and corneal scars were operated. Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest and cycloplegic refraction, and corneal topography, with asphericity and regularity, were analyzed. LASIK (n = 10) and photorefractive keratectomy (n = 6) were performed using the ALLEGRETTO WAVE excimer laser and T-CAT software (Topography-guided Customized Ablation Treatment; WaveLight Laser Technologie AG, Erlangen, Germany).
  
  
  RESULTS
  In the LASIK group, UCVA improved from 0.81 +/- 0.68 IogMAR (20/130) (range: 0.2 to 2.0) to 0.29 +/- 0.21 logMAR (20/39) (range: 0.1 to 0.7) at 6 months. In the PRK group, mean UCVA improved from 0.89 +/- 0.87 IogMAR (20/157) (range: 0.1 to 2.0) to 0.42 +/- 0.35 logMAR (20/53) (range: 0.1 to 1.0) at 6 months. Best spectacle-corrected visual acuity did not change significantly in either group. One PRK patient lost one line of BSCVA. Refractive cylinder for the LASIK group improved from -2.53 +/- 1.71 diopters (D) (range: -0.75 to -5.75 D) to -1.28 +/- 0.99 D (range: 0 to -2.50 D) at 6 months. Refractive cylinder in the PRK group improved from -2.21 +/- 2.11 D (range: -0.25 to -5.50 D) to -1.10 +/- 0.42 D (range: -0.50 to -1.50 D). Index of surface irregularity showed a decrease from 60 +/- 12 (range: 46 to 89) to 50 +/- 9 (range: 32 to 63) at 6 months in the LASIK group whereas no significant change was noted in the PRK group. Subjective symptoms, such as glare, halos, ghost images, starbursts, and monocular diplopia, were not present postoperatively.
  
  
  CONCLUSIONS
  Topography-guided LASIK and PRK resulted in a significant reduction of refractive cylinder and increase of UCVA, without a significant loss of BSCVA.
authors.affiliation: Vardinoyiannion Eye Institute of Crete, University of Crete, PO Box 1352, 71110 Voutes, Heraklion Crete, Greece. visioncare@mac.com
authors.forename: Mirko R
authors.initials: MR
authors.lastname: Jankov
authors.forename: Sophia I
authors.initials: SI
authors.lastname: Panagopoulou
authors.forename: Nikolaos S
authors.initials: NS
authors.lastname: Tsiklis
authors.forename: Georgos C
authors.initials: GC
authors.lastname: Hajitanasis
authors.forename: loannis M
authors.initials: lM
authors.lastname: Aslanides
authors.forename: loannis G
authors.initials: lG
authors.lastname: Pallikaris
mesh_terms: D000293:Adolescent; D000328:Adult; D001251:Astigmatism / Q000473:pathology / Q000601:surgery*; D003315:Cornea / Q000473:pathology* / Q000601:surgery; D019781:Corneal Topography; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods; D054018:Lasers, Excimer; D008297:Male; D018903:Photorefractive Keratectomy / Q000379:methods*; D011446:Prospective Studies; D012029:Refraction, Ocular; D012720:Severity of Illness Index; D014792:Visual Acuity