title: Excimer retreatment for myopic photorefractive keratectomy failures. Six- to 18-month follow-up.
abstract: OBJECTIVE
  To study the results of retreatment after myopic photorefractive keratectomy in 22 patients. Five patients showed regression and 17 showed undercorrection combined with regression. The follow-up was 6 to 18 months.
  
  
  METHODS
  A laser was used with a fluence of 160 mJ/cm2 at a frequency of 5 Hz. The same nomogram used for the initial treatment was used for the retreatment. No nitrogen purge was used. Fluorometholone 0.1% four times daily tapered over 4 months was applied postoperatively except in five patients.
  
  
  RESULTS
  There was no untoward effect in any patient who had retreatment. The mean preoperative spherical equivalent before retreatment was -2.61 +/- 1.62 diopters (D) (range, -1.00 to -6.63 D). After 1 year, the mean spherical equivalent was -0.84 +/- 1.22 D (range, 0.00 to -4.88 D) and at 18 months it was -1.31 +/-1.60 D (range, 0.00 to -5.13 D). Spherical equivalent was +/- D in 82% of patients at 1 year and in 67% at 18 months. Uncorrected visual acuity was 20/40 or better at 1 year in 77% of patients and 20/20 or better in 55%; at 18 months, it was 20/40 or better in 67%.
  
  
  CONCLUSIONS
  Retreatment may be considered for undercorrection and/or regression in photorefractive keratectomy. No complications were observed, and there is appreciable improvement in the final results. The refraction 6 months after retreatment is stable with no statistically significant change from 6 to 12 months (Student's t=0.51; P=0.62) and 6 to 18 months (Student's t=1.0l; P=0.33).
authors.affiliation: University of Missouri-Kansas City, Department of Ophthalmology, Eye Foundation, 64108, USA.
authors.forename: C S
authors.initials: CS
authors.lastname: Matta
authors.forename: L W
authors.initials: LW
authors.lastname: Piebenga
authors.forename: M R
authors.initials: MR
authors.lastname: Deitz
authors.forename: J
authors.initials: J
authors.lastname: Tauber
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000209:etiology; D015350:Contrast Sensitivity; D003315:Cornea / Q000502:physiology / Q000601:surgery*; D003318:Corneal Opacity / Q000209:etiology; D004848:Epithelium / Q000502:physiology; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000209:etiology / Q000601:surgery*; D010149:Postoperative Pain / Q000209:etiology; D018903:Photorefractive Keratectomy / Q000009:adverse effects; D012029:Refraction, Ocular; D012086:Reoperation; D017211:Treatment Failure; D014792:Visual Acuity; D014945:Wound Healing