title: Effect of hinge position on corneal sensation and dry eye parameters after femtosecond laser-assisted LASIK.
abstract: OBJECTIVE
  To evaluate the effect of superior- versus nasal-hinged flaps on corneal sensation and dry eye after femtosecond laser-assisted LASIK.
  
  
  METHODS
  A total of 43 patients who had undergone bilateral femtosecond laser-assisted LASIK for myopia were evaluated in a prospective, nonrandomized, contralateral eye study to compare the difference between different hinges on corneal sensation and dry eye. Corneal esthesiometry, Schirmer basic tear secretion test (BST), tear break-up time (BUT), ocular surface stainings, and the Ocular Surface Disease Index (OSDI) questionnaire were used to evaluate corneal sensation and dry eye parameters preoperatively as well as at 1 week and 1, 3, and 6 months postoperatively.
  
  
  RESULTS
  Corneal sensation decreased significantly in both groups 1 week after surgery (P<.05 in the nasal hinge group; P<.01 in the superior hinge group) and gradually recovered over the first 3 months. No significant change was noted in BUT after surgery in either group (P>.05). Significant increases were noted in BST values at 1 and 3 months (P<.05) and 6 months (P<.01) postoperatively in both groups. Corneal fluorescein staining increased significantly in both groups at 1 week (P<.01) and returned to baseline by 6 months. Conjunctival Rose Bengal staining decreased significantly by 6 months in the superior hinge group only (P<.05). The OSDI significantly increased 1 week after surgery (P<.01) and did not completely return to baseline by 6 months postoperatively in either group (P<.05). No significant differences were noted in any of the parameters between groups at any time point (P>.05).
  
  
  CONCLUSIONS
  Hinge position had no significant effect on corneal sensation or dry eye parameters. Aggressive dry eye regimens are needed for patients with preoperative dry eye.
authors.affiliation: Department of Ophthalmology, Chang Gung Memorial Hospital, Keelung, Taiwan.
authors.forename: Jerry Chien-Chieh
authors.initials: JC
authors.lastname: Huang
authors.forename: Chi-Chin
authors.initials: CC
authors.lastname: Sun
authors.forename: Chao-Kay
authors.initials: CK
authors.lastname: Chang
authors.forename: David Hui-Kang
authors.initials: DH
authors.lastname: Ma
authors.forename: Yi-Fang
authors.initials: YF
authors.lastname: Lin
mesh_terms: D000328:Adult; D003315:Cornea / Q000502:physiology*; D003319:Corneal Stroma / Q000601:surgery; D015352:Dry Eye Syndromes / Q000503:physiopathology*; D005260:Female; D005456:Fluorescent Dyes; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000379:methods*; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D011446:Prospective Studies; D012395:Rose Bengal; D012677:Sensation / Q000502:physiology*; D013524:Surgical Flaps; D011795:Surveys and Questionnaires; D013666:Tears / Q000737:chemistry / Q000502:physiology; D055815:Young Adult
chemical_list: D005456:Fluorescent Dyes; D012395:Rose Bengal