title: Double zone PRK for high myopia.
abstract: BACKGROUND
  Although excimer laser PRK is our operation of choice for treating myopia, the correction of myopia exceeding -8.00 dpt is still a challenge as this procedure requires a deeper keratectomy. Therefore a double zone treatment may be beneficial to reduce ablation depth.
  
  
  METHODS
  Twenty-one eyes with myopia between -8.00 dpt and -14.00 dpt were included in this study. Twelve eyes were treated 60% of myopia by 5 mm zone and the remaining 40% in a 4 mm zone in the same session (Group 1).
  
  
  RESULTS
  Nine eyes achieved 60% of the desired correction treated with a 4 mm zone whereas 40% correction was achieved in a 5 mm zone (Group 2). No significant difference in postoperative healing, pain, hyperopic shift, myopic regression and haze was observed at the end of the mean follow-up time (10.4 months) but photophobic complaints were less in Group 2. Best corrected visual acuity did not decrease significantly.
  
  
  CONCLUSIONS
  Double zone treatment seems to be an interesting method for treating moderate to high myopia.
authors.affiliation: University of Istanbul, Cerrahpasa.
authors.forename: T
authors.initials: T
authors.lastname: Aktunç
authors.forename: R
authors.initials: R
authors.lastname: Aktunç
authors.forename: H
authors.initials: H
authors.lastname: Bahçecioglu
mesh_terms: D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D009216:Myopia / Q000145:classification / Q000601:surgery*; D018903:Photorefractive Keratectomy / Q000295:instrumentation*; D011183:Postoperative Complications / Q000209:etiology; D012029:Refraction, Ocular; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology