title: Histopathology of epi-LASIK in eyes with virgin corneas and eyes with previously altered corneas.
abstract: OBJECTIVE
  To perform a histological analysis of free epithelial flaps that were intentionally created with an Epi-K epikeratome (Moria S.A.) during epi-LASIK in eyes with virgin corneas and eyes with previous corneal surgery or keratoconus.
  
  
  METHODS
  Vissum-Instituto Oftalmológico de Alicante, Alicante, Spain.
  
  
  METHODS
  This prospective and consecutive case series comprised 18 free flaps obtained from 18 patients. Twelve patients had virgin corneas, and 6 had altered corneas from previous surgery, trauma, or keratoconus. The flaps were fixed in 4% buffered formaldehyde (pH 7) for posterior histopathological analysis. Serial cuts of each flap were performed, and the sheets were stained with hematoxylin-eosin and periodic acid-Schiff. The main outcome measure was the histopathology of the corneal flaps.
  
  
  RESULTS
  All flaps from virgin corneas consisted entirely of epithelium without residual stromal tissue or Bowman's layer. Histopathological analysis of the flaps after epi-LASIK in patients with previously altered corneas showed varying levels of stroma in all cases.
  
  
  CONCLUSIONS
  Epi-LASIK with the Epi-K epikeratome effectively cleaved the epithelium from Bowman's layer in healthy corneas; however, when the integrity of Bowman's layer is compromised, epi-LASIK should be avoided as stromal invasion will likely occur.
authors.affiliation: Vissum-Instituto Oftalmológico Alicante, Alicante, Spain. jlalio@vissum.com
authors.forename: Jorge L
authors.initials: JL
authors.lastname: Alió
authors.forename: Alejandra E
authors.initials: AE
authors.lastname: Rodriguez
authors.forename: Maria C
authors.initials: MC
authors.lastname: Mendez
authors.forename: John
authors.initials: J
authors.lastname: Kanellopoulos
mesh_terms: D000328:Adult; D050541:Bowman Membrane / Q000473:pathology; D003319:Corneal Stroma / Q000473:pathology* / Q000601:surgery; D019573:Epithelium, Corneal / Q000473:pathology*; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D011446:Prospective Studies; D013524:Surgical Flaps / Q000473:pathology*