title: Fifteen years follow-up of photorefractive keratectomy up to 10 D of myopia: outcomes and analysis of the refractive regression.
abstract: OBJECTIVE
  To evaluate outcomes of photorefractive keratectomy up to -10.00 D of myopia and -4.50 of astigmatism and to develop a predictive model for the refractive changes in the long term.
  
  
  METHODS
  Vissum Corporation and Miguel Hernandez University (Alicante, Spain).
  
  
  METHODS
  Retrospective-prospective observational series of cases.
  
  
  METHODS
  This study included 33 eyes of 33 patients aged 46.79±7.04 years (range 40-57) operated with the VISX 20/20 excimer laser with optical zones of 6 mm. No mitomycin C was used in any of these cases. The minimum follow-up was 15 years. The main outcome measures were: uncorrected and corrected distance visual acuity, manifest refraction and corneal topography. Linear regression models were developed from the observed refractive changes over time.
  
  
  RESULTS
  Safety and efficacy indexes at 15 years were 1.18 and 0.83, respectively. No statistically significant differences were detected for any keratometric variable during the follow-up (p≥0.103). 15 years after the surgery 54.55% of the eyes were within ±1.00 D of spherical equivalent and 84.85% within ±2.00 D. The uncorrected distance visual acuity at 15 years was 20/25 or better in 60.6% of the eyes and 20/40 or better in 72.73% of the eyes. The correlation between the attempted and the achieved refractions was r=0.948 (p<0.001) at 1 year, and r=0.821 (p<0.001) at 15 years. No corneal ectasia was detected in any case during the follow-up.
  
  
  CONCLUSIONS
  Photorefractive keratectomy is a safe refractive procedure in the long term within the range of myopia currently considered suitable for its use, although its efficacy decreases with time, especially, in high myopia. The model developed predicts a myopic regression of 2.00 D at 15 years for an ablation depth of 130 µm.
authors.affiliation: Vissum Corporación, Alicante, Spain Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain.
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Alio
authors.affiliation: Vissum Corporación, Alicante, Spain.
authors.forename: Felipe A
authors.initials: FA
authors.lastname: Soria
authors.affiliation: Vissum Corporación, Alicante, Spain.
authors.forename: Alessandro
authors.initials: A
authors.lastname: Abbouda
authors.affiliation: Division of Ophthalmology, Universidad Miguel Hernández, Alicante, Spain.
authors.forename: Pablo
authors.initials: P
authors.lastname: Peña-García
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery*; D063171:Corneal Pachymetry; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D008954:Models, Biological; D047728:Myopia, Degenerative / Q000503:physiopathology / Q000601:surgery*; D018903:Photorefractive Keratectomy; D011446:Prospective Studies; D012029:Refraction, Ocular / Q000502:physiology*; D012189:Retrospective Studies; D014792:Visual Acuity / Q000502:physiology
keywords: Cornea