title: Two-zone excimer photorefractive keratectomy for moderate myopia. Six- to 18-month follow-up.
abstract: OBJECTIVE
  To study the results of the two-zone photorefractive keratectomy (PRK) in 35 eyes of 27 patients with moderate myopia of 6 to 8 diopters (D) over 6 to 18 months.
  
  
  METHODS
  An excimer laser was used with a fluence of 160 mJ/cm2 at a frequency of 5 Hz. The ablation was performed with two zones (6 and 5 mm). All patients received topical steroid (0.1 fluorometholone) tapered over 4 months.
  
  
  RESULTS
  There were no significant untoward effects in any patient. There were minimal changes in contrast sensitivity, brightness acuity, and astigmatism. Uncorrected visual acuity of 20/40 or better was obtained in 77% of patients at 6 months, in 73% at 12 months, and in 71% at 18 months. A refraction of +/-1.0 diopter was obtained in 69% at 6 months, in 65% at 12 months, and in 71% at 18 months. There is no statistically significant difference at 6, 12, and 18 months in both visual acuity and refraction.
  
  
  CONCLUSIONS
  Two-zone PRK in moderate myopia is safe and reasonably effective. The results are stable from 6 to 18 months.
authors.affiliation: Department of Ophthalmology Eye Foundation, University of Missouri, Kansas City 64108, USA.
authors.forename: L W
authors.initials: LW
authors.lastname: Piebenga
authors.forename: C S
authors.initials: CS
authors.lastname: Matta
authors.forename: M R
authors.initials: MR
authors.lastname: Deitz
authors.forename: J
authors.initials: J
authors.lastname: Tauber
mesh_terms: D000287:Administration, Topical; D000328:Adult; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage; D001251:Astigmatism / Q000503:physiopathology; D015350:Contrast Sensitivity / Q000502:physiology; D003315:Cornea / Q000187:drug effects / Q000503:physiopathology / Q000601:surgery*; D003318:Corneal Opacity / Q000503:physiopathology; D005260:Female; D005469:Fluorometholone / Q000008:administration & dosage; D005500:Follow-Up Studies; D005938:Glucocorticoids; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000188:drug therapy / Q000503:physiopathology / Q000601:surgery*; D009883:Ophthalmic Solutions; D010149:Postoperative Pain / Q000503:physiopathology; D018903:Photorefractive Keratectomy; D011183:Postoperative Complications; D012029:Refraction, Ocular; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology; D014945:Wound Healing / Q000502:physiology
chemical_list: D000893:Anti-Inflammatory Agents; D005938:Glucocorticoids; D009883:Ophthalmic Solutions; D005469:Fluorometholone