title: Comparison of real-time intraocular pressure during laser in situ keratomileusis and epithelial laser in situ keratomileusis in porcine eyes.
abstract: OBJECTIVE
  To compare real-time intraocular pressure (IOP) between laser in situ keratomileusis (LASIK) and epithelial LASIK (epi-LASIK) in porcine eyes during flap creation using a microkeratome or an epikeratome, respectively.
  
  
  METHODS
  Vissum Madrid, Madrid, Spain.
  
  
  METHODS
  In this prospective study, a Moria microkeratome was used in 1 eye (LASIK group) and an Epi-K epikeratome in the other eye (epi-LASIK group) to create a lamellar corneal flap and an epithelial flap, respectively, in freshly enucleated porcine eyes. The IOP changes during the procedures were recorded by direct cannulation using a reusable blood pressure transducer connected to the anterior chamber.
  
  
  RESULTS
  Each group comprised 17 eyes. In the LASIK group, the mean IOP was 113.65 mm Hg +/- 10.78 (SD) during suctioning and 112.35 +/- 11.51 mm Hg during cutting phases. The mean duration of the phases was 9.00 +/- 1.46 seconds and 6.06 +/- 1.14 seconds, respectively. In the epi-LASIK group, the mean IOP was 92.57 +/- 20.86 mm Hg during suctioning, 82.09 +/- 20 mm Hg during cutting, and 67.28 +/- 13.49 during low vacuum. The mean duration of the phases was 25.88 +/- 1.96 seconds, 33.82 +/- 2.81 seconds, and 29.71 +/- 3.29 seconds, respectively. The IOP values were significantly different between the 2 groups (all comparisons P<.05).
  
  
  CONCLUSIONS
  Real-time IOP measured during suctioning and flap creation by direct cannulation of the anterior chamber in freshly enucleated porcine eyes showed a significant increase in IOP during LASIK and epi-LASIK; the increase was lower in the epi-LASIK group.
authors.affiliation: Vissum Madrid, Santa Hortensia 58, 28002 Madrid, Spain. jlhernandez@cnoo.es
authors.forename: José L
authors.initials: JL
authors.lastname: Hernández-Verdejo
authors.forename: Laura
authors.initials: L
authors.lastname: de Benito-Llopis
authors.forename: Miguel A
authors.initials: MA
authors.lastname: Teus
mesh_terms: D000818:Animals; D003199:Computer Systems; D003319:Corneal Stroma / Q000601:surgery*; D019573:Epithelium, Corneal / Q000601:surgery*; D007429:Intraocular Pressure / Q000502:physiology*; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D011446:Prospective Studies; D013396:Suction; D013524:Surgical Flaps; D013552:Swine; D014065:Tonometry, Ocular / Q000379:methods