title: Profiles of intraocular pressure in human donor eyes during femtosecond laser procedures--a comparative study.
abstract: OBJECTIVE
  To compare four different femtosecond laser devices (IntraLase FS, Zeiss VisuMAX, and Ziemer Femto LDV, and a prototype Schwind SmartTech Nanolaser) in human donor eyes with regard to their effects on IOP during femtosecond laser flap cutting. In order to get cuts parallel to the corneal surface, the cornea has to be forced into a defined shape and current femtosecond laser devices either use a flat or a curved patient interface design to achieve applanation.
  
  
  METHODS
  IOP was measured in enucleated eyeballs (n = 46) not suitable for keratoplasty by direct cannulation of the vitreous body. A second cannula was inserted to adjust IOP to a baseline pressure of 20 mm Hg. The eyeballs were lifted by custom made supporting stands to achieve an appropriate height and put under the femto-LASIK devices.
  
  
  RESULTS
  The flat patient interfaces gave rise to higher IOPs (IOP max = 328.3 ± 29.8, 228.8 ± 28.4, and 201.09 ± 21.4 mm Hg), whereas the curved patient interface caused lower IOPs in response to attachment and suction (IOP max = 104.9 ± 13.4 mm Hg).
  
  
  CONCLUSIONS
  Based on previous findings of visual field defects after LASIK, and as a consequence of the present study, it seems feasible to design patient interfaces in a more physiologic manner to prevent high IOPs during refractive procedures.
authors.affiliation: Department of Ophthalmology, University Hospital Salzburg/Paracelsus Medical University, Salzburg, Austria.
authors.forename: Clemens
authors.initials: C
authors.lastname: Strohmaier
authors.forename: Christian
authors.initials: C
authors.lastname: Runge
authors.forename: Orang
authors.initials: O
authors.lastname: Seyeddain
authors.forename: Martin
authors.initials: M
authors.lastname: Emesz
authors.forename: Christian
authors.initials: C
authors.lastname: Nischler
authors.forename: Alois
authors.initials: A
authors.lastname: Dexl
authors.forename: Günther
authors.initials: G
authors.lastname: Grabner
authors.forename: Herbert A
authors.initials: HA
authors.lastname: Reitsamer
mesh_terms: D003319:Corneal Stroma / Q000601:surgery*; D006801:Humans; D007429:Intraocular Pressure / Q000502:physiology*; D020731:Keratomileusis, Laser In Situ / Q000295:instrumentation*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008875:Middle Aged; D008954:Models, Biological; D013524:Surgical Flaps; D014019:Tissue Donors; D014065:Tonometry, Ocular