title: Effect of hinge position on corneal sensation and dry eye after laser in situ keratomileusis using a femtosecond laser.
abstract: OBJECTIVE
  To determine whether hinge position has an effect on corneal sensation and dry-eye symptoms after myopic laser in situ keratomileusis (LASIK) performed with the IntraLase femtosecond laser (IntraLase Corp.).
  
  
  METHODS
  University-based academic practice, Ann Arbor, Michigan, USA.
  
  
  METHODS
  Sixty-six consecutive eyes of 33 patients were prospectively evaluated in a randomized contralateral-eye study to compare the difference between superior-hinge and temporal-hinge locations after bilateral myopic LASIK with the IntraLase femtosecond laser. Central Cochet-Bonnet esthesiometry, the Ocular Surface Disease Index (OSDI) questionnaire, Schirmer test with anesthesia, tear breakup time (TBUT), corneal fluorescein, and conjunctival lissamine green staining were evaluated preoperatively as well as 1 week and 1, 3, 6, and 12 months after surgery.
  
  
  RESULTS
  Corneal sensation was reduced with both superior-hinged and temporal-hinged LASIK flaps 1 week and 1, 3, 6, and 12 months after surgery (P<.0001). There was no difference in corneal sensation between superior-hinged and temporal-hinged flaps at any time point. The OSDI score was increased in 22.6% of patients at 1 week and 21.9% at 1 month (P<.00001), and corneal fluorescein staining was increased in 18% at 1 week. There were no differences in the OSDI, Schirmer with anesthesia, TBUT, corneal fluorescein, or conjunctival lissamine green staining when preoperative values and hinge location were compared.
  
  
  CONCLUSIONS
  Mild dry-eye disease was present early after myopic LASIK with the IntraLase laser. Hinge position had no effect on central corneal sensation or dry-eye disease.
authors.affiliation: Department of Ophthalmology and Visual Sciences, W.K. Kellogg Eye Center, University of Michigan Medical School, Ann Arbor, Michigan 48105, USA. smian@umich.edu
authors.forename: Shahzad I
authors.initials: SI
authors.lastname: Mian
authors.forename: Roni M
authors.initials: RM
authors.lastname: Shtein
authors.forename: Ariana
authors.initials: A
authors.lastname: Nelson
authors.forename: David C
authors.initials: DC
authors.lastname: Musch
mesh_terms: D000328:Adult; D000368:Aged; D003315:Cornea / Q000503:physiopathology*; D015352:Dry Eye Syndromes / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D006987:Hypesthesia / Q000209:etiology / Q000503:physiopathology*; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D012677:Sensation / Q000502:physiology; D013524:Surgical Flaps