title: Incidence of epithelial ingrowth in primary and retreatment laser in situ keratomileusis.
abstract: OBJECTIVE
  To analyze the risk for clinically significant epithelial ingrowth after primary laser in situ keratomileusis (LASIK) and flap-lift retreatment LASIK.
  
  
  METHODS
  Private practice, Beverly Hills, California, USA.
  
  
  METHODS
  All cases of primary and flap-lift retreatment LASIK performed by the same surgeon in a single surgical center between January 2004 and June 2007 were retrospectively reviewed. Cases that subsequently developed clinically significant epithelial ingrowth, defined as epithelial ingrowth impeding on the visual axis and negatively affecting uncorrected or corrected distance visual acuity, were identified and analyzed.
  
  
  RESULTS
  Clinically significant epithelial ingrowth occurred in none of the 3866 primary LASIK cases and in 15 (2.3%) of the 646 flap-lift retreatment cases (P<.0001). Clinically significant ingrowth was more frequent when flap-lift retreatment was performed 3 or more years after primary LASIK (7.7% versus 1.0%) (P = .0001). Patient age and sex did not have a statistically significant effect on the epithelial ingrowth rate. There was a nonsignificant trend toward increased epithelial ingrowth after flap-lift retreatment of Automated Corneal Shaper (ACS) microkeratome flaps.
  
  
  CONCLUSIONS
  Flap-lift retreatment performed 3 or more years after primary LASIK led to a higher risk of clinically significant epithelial ingrowth than primary LASIK or earlier flap-lift retreatment.
  
  
  BACKGROUND
  The author has no financial or proprietary interest in any material or method mentioned.
authors.affiliation: Caster Eye Center Medical Group, 9100 Wilshire Boulevard, Suite 265 E, Beverly Hills, California 90212, USA. acaster@castervision.com
authors.forename: Andrew I
authors.initials: AI
authors.lastname: Caster
authors.forename: David W
authors.initials: DW
authors.lastname: Friess
authors.forename: Frank J
authors.initials: FJ
authors.lastname: Schwendeman
mesh_terms: D000328:Adult; D000368:Aged; D003316:Corneal Diseases / Q000175:diagnosis / Q000209:etiology* / Q000601:surgery; D003319:Corneal Stroma / Q000601:surgery; D004847:Epithelial Cells / Q000473:pathology; D019573:Epithelium, Corneal / Q000473:pathology*; D005260:Female; D006801:Humans; D015994:Incidence; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery; D011183:Postoperative Complications; D012086:Reoperation; D012189:Retrospective Studies; D018570:Risk Assessment; D013524:Surgical Flaps; D014792:Visual Acuity / Q000502:physiology; D055815:Young Adult