title: Long-term results of photorefractive keratectomy for myopia and myopic astigmatism.
abstract: OBJECTIVE
  To assess the long-term refractive outcomes of photorefractive keratectomy in myopia and myopic astigmatism.
  
  
  METHODS
  A retrospective study of 120 photorefractive keratectomy operated eyes with at least four-year follow-up (maximum of 96 months, mean follow-up 55 months). We divided patients into group 1 (G1) spherical equivalent (SE) up to -4.00 diopters (D) and group 2 (G2) SE >-4.00 D. The Summit Apex Plus excimer laser was used for ablation. All eyes were analyzed in terms of uncorrected and best spectacle corrected visual acuity (UCVA/BSCVA) and cycloplegic refraction. Data were analyzed using the Refractive Surgery Consultant Elite database software.
  
  
  RESULTS
  G1 with 85 eyes (49 patients) presented mean SE -2.42 D and G2 with 35 eyes (22 patients) and mean SE of -4.45 D. Ninety-four percent of eyes in G1 and 82.9% of G2 were within +/-1.00 D of emmetropia at 4 years. The UCVA was 20/30 or better in 82.0% of G1 eyes and 77.0% of G2 in the last postoperative follow-up. No patient lost more than one line in G2 compared to 13.0% in G1. Eyes that gained one or more lines after 4-year follow-up were 11.9% G1 and 2.9% in G2, respectively. A statistically significant positive correlation was found between achieved versus attempted refractive correction in both groups (r=0.925, p<0.0005).
  
  
  CONCLUSIONS
  Photorefractive keratectomy was a safe and stable surgical procedure to correct myopic refractive errors, with no significant change in mean postoperative spherical equivalent refraction in the long-term follow-up.
authors.affiliation: Departamento de Oftalmologia, Universidade Federal de São Paulo, São Paulo, SP, Brasil. ester.yamazaki@gmail.com
authors.forename: Ester Sakae
authors.initials: ES
authors.lastname: Yamazaki
authors.forename: Iane
authors.initials: I
authors.lastname: Stillitano
authors.forename: Anelise Dutra
authors.initials: AD
authors.lastname: Wallau
authors.forename: Juliana Mantovani
authors.initials: JM
authors.lastname: Bottós
authors.forename: Mauro
authors.initials: M
authors.lastname: Campos
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000503:physiopathology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D054018:Lasers, Excimer; D016014:Linear Models; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery; D018903:Photorefractive Keratectomy; D011184:Postoperative Period; D012029:Refraction, Ocular / Q000502:physiology; D012189:Retrospective Studies; D012449:Safety; D013997:Time Factors; D016896:Treatment Outcome; D014792:Visual Acuity / Q000502:physiology