title: First results with wavefront-guided photorefractive keratectomy for hyperopia.
abstract: OBJECTIVE
  To compare the results of traditional laser photoablation and wavefront-supported customized ablation (WASCA) in hyperopic photorefractive keratectomy (H-PRK).
  
  
  METHODS
  This was a prospective study, comparing two treatment groups, each comprising 40 eyes of 20 patients. Wavefront aberrations were examined using a Shack-Hartmann aberrometer. Preoperative refraction was similar in the two groups; in the traditional H-PRK group (Group 1) it was +3.10 +/- 0.85 D, and in the WASCA-guided group (Group 2) it was +2.90 +/- 0.80 D. H-PRK was performed with the Asclepion-Meditec MEL 70 flying-spot excimer laser. The follow-up time was 6 months.
  
  
  RESULTS
  In Group 1, mean postoperative refraction was +0.14 +/- 0.24 D, and in Group 2, -0.10 +/- 0.25 D; mean uncorrected visual acuity was 0.92 +/- 0.16 in Group 1 and 0.95 +/- 0.18 in Group 2. Mean best spectacle-corrected visual acuity was 0.96 +/- 0.04 in Group 1 and 1.06 +/- 0.13 in Group 2. In Group 1, 67.5% (27 of 40 eyes), and in Group 2, 85% (34 of 40 eyes) were within +/-0.50 D of target refraction. Regarding change of spectacle-corrected visual acuity in Group 1, 5% (2 of 40 eyes), and in Group 2, 20% (8 of 40 eyes) gained one Snellen line compared to the preoperative; in Group 1, 10% (4 of 40 eyes), and in Group 2, 12.5% (5 of 40 eyes) lost two Snellen lines. In Group 2, the root mean square value for the higher order aberration increased from the initial 0.134 to 0.257 microm at 6 months after surgery.
  
  
  CONCLUSIONS
  WASCA-guided hyperopic-PRK treatment was found to be safe and predictable. The results were better than those achieved with traditional PRK performed using the same flying-spot type excimer laser.
mesh_terms: D000328:Adult; D003315:Cornea / Q000601:surgery*; D005260:Female; D006801:Humans; D006956:Hyperopia / Q000601:surgery*; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D018903:Photorefractive Keratectomy / Q000379:methods*; D011446:Prospective Studies; D012029:Refraction, Ocular; D012449:Safety; D016896:Treatment Outcome; D014792:Visual Acuity