title: Elliptical ELSA (LASEK) instruments for the treatment of astigmatism.
abstract: OBJECTIVE
  To investigate newly designed, elliptical ELSA (excimer laser subepithelial ablation) instruments for the treatment of astigmatism.
  
  
  METHODS
  University Eye Clinic Regensburg, Regensburg, Germany, and the Rayne Institute, Department of Ophthalmology, St. Thomas' Hospital, London, United Kingdom.
  
  
  METHODS
  The new ELSA instrument set consists of an elliptical microtrephine (11.0 mm x 8.0 mm) with a 70 microm calibrated blade and an elliptical alcohol cone (11.5 mm x 8.5 mm). With this instrument set, ELSA (the laser-assisted subepithelial keratectomy [LASEK] described by Camellin) was performed in 34 astigmatic eyes. The cylindrical correction was between 1.00 diopters (D) and 3.50 D and the spherical correction, between -0.75 D and -8.75 D. In all eyes, the follow-up was 6 months. The postoperative refractive outcome was analyzed using Alpins vector analysis.
  
  
  RESULTS
  Excimer laser subepithelial ablation was performed without intraoperative complications in all eyes. At 6 months, the mean spherical correction was -0.04 D +/- 0.27 (SD) (range +0.75 to -0.75 D) and the mean cylindrical correction, 0.27 +/- 0.23 D (range 0 to 0.75 D). The mean index of success was 0.18 +/- 0.15.
  
  
  CONCLUSIONS
  With the elliptical instruments, ELSA was an effective and safe surgical procedure for astigmatism.
authors.affiliation: From University Eye Clinic Regensburg, Regensburg, Germany. lohmann@eye-regensburg.de
authors.forename: Chris P
authors.initials: CP
authors.lastname: Lohmann
authors.forename: Christoph Winkler
authors.initials: CW
authors.lastname: von Mohrenfels
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Herrmann
authors.forename: Bernhard
authors.initials: B
authors.lastname: Gabler
authors.forename: Thomas
authors.initials: T
authors.lastname: Laube
authors.forename: John
authors.initials: J
authors.lastname: Marshall
mesh_terms: D001251:Astigmatism / Q000601:surgery*; D019781:Corneal Topography; D004847:Epithelial Cells; D019573:Epithelium, Corneal / Q000601:surgery; D004867:Equipment Design; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000295:instrumentation* / Q000379:methods; D012029:Refraction, Ocular; D012449:Safety; D013524:Surgical Flaps; D014792:Visual Acuity