title: Paracentral photoablations to correct higher grades of naturally occurring astigmatism.
abstract: OBJECTIVE
  To evaluate the efficacy of paracentral ablations in treating higher degrees of naturally occurring myopic and hyperopic astigmatism.
  
  
  METHODS
  Augenklinik, Kreiskrankenhaus Bad Hersfeld, Germany.
  
  
  METHODS
  Twenty-five eyes (7 with hyperopia, 18 with myopia) with naturally occurring corneal astigmatism greater than 1.75 diopters (D) were treated by excimer laser. The mean refractive cylinder was -4.05 D +/- 1.46 (SD) (range -1.75 to -7.00 D). The intention was to reduce the astigmatism without consideration of the spherical refractive error. Two paracentral ablations were performed by photorefractive keratectomy with treatment zones of 3.5 mm in the flatter meridian of the cornea. Objective refraction, best corrected visual acuity (BCVA), changes in corneal radius, development of haze, and regression were recorded.
  
  
  RESULTS
  The paracentral ablations induced a steepening of the corneal radius in the flatter meridian from 8.12 mm (mean preoperative value) to 7. 84 mm (mean postoperative value) and thus reduced the mean refractive cylinder to -1.12 +/- 0.82 D (range 0.00 to - 3.00 D), corresponding to a mean reduction of 78%. No eye experienced a loss of Snellen lines. The preoperative BCVA (mean 20/25; range 20/50 to 20/20) was unchanged postoperatively
  
  
  CONCLUSIONS
  Paracentral ablations resulted in a stable corneal curvature immediately after epithelial healing, with a moderate regression over time. Paracentral ablations with the excimer laser appear to be a safe and effective method to correct higher grades of corneal astigmatism.
authors.affiliation: Augenklinik, Kreiskrankenhaus Bad Hersfeld, Bad Hersfeld, Germany.
authors.forename: W W
authors.initials: WW
authors.lastname: Huetz
authors.forename: P C
authors.initials: PC
authors.lastname: Hoffmann
authors.forename: H B
authors.initials: HB
authors.lastname: Eckhardt
authors.forename: A
authors.initials: A
authors.lastname: Heuring
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000150:complications / Q000601:surgery*; D003315:Cornea / Q000601:surgery*; D019781:Corneal Topography; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000150:complications; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000150:complications; D018903:Photorefractive Keratectomy / Q000379:methods*; D012029:Refraction, Ocular; D016896:Treatment Outcome; D014792:Visual Acuity; D014945:Wound Healing