title: Schirmer test values and the outcome of photorefractive keratectomy.
abstract: OBJECTIVE
  To evaluate whether relative tear deficiency, indicated by low standardized Schirmer test values, influences the outcome of photorefractive keratectomy (PRK).
  
  
  METHODS
  Department of Ophthalmology, University of Heisinki, Finland.
  
  
  METHODS
  Sixty-two patients were pair-matched by age and attempted myopic correction. They were divided into two groups: Group 1 (n = 31) comprised patients with standardized, eye-closed Schirmer test values of < or = 6 mm/5 min; Group 2 (n = 31), patients with Schirmer test values of > or = 10 mm/5 min. None of the eyes showed clinical signs of dry eye on slitlamp examination. Follow-up was 12 months.
  
  
  RESULTS
  At 1 year, the visual acuity was 0.5 or better in 68.4% of Group 1 eyes and in 78.9% of Group 2 eyes. In Groups 1 and 2, 55.6% of eyes and 52.6%, respectively, were within 1.50 diopter (D) of attempted correction and 83.3% and 89.5%, respectively, were within 1.00 D. At 6 months, the mean overcorrection was + 1.32 +/- 1.13 D in Group 1 and + 0.77 +/- 0.57 D in Group 2 and at 1 year, + 0.96 +/- 1.13 D and +0.58 +/- 0.37 D, respectively. There was no difference between the two groups in visual acuity and obtained refractive correction or haze score at any postoperative examination. The minor tendency toward overcorrection in Group 1 could not be confirmed statistically.
  
  
  CONCLUSIONS
  Subclinical tear deficiency indicated by low Schirmer test values did not influence the PRK outcome in patients matched by age and magnitude of refractive correction.
authors.affiliation: Department of Ophthalmology, University of Helsinki, Finland.
authors.forename: T H
authors.initials: TH
authors.lastname: Tuunanen
authors.forename: T M
authors.initials: TM
authors.lastname: Tervo
mesh_terms: D000328:Adult; D003315:Cornea / Q000378:metabolism / Q000503:physiopathology / Q000601:surgery*; D005500:Follow-Up Studies; D006801:Humans; D054018:Lasers, Excimer; D008875:Middle Aged; D009216:Myopia / Q000378:metabolism / Q000503:physiopathology / Q000601:surgery*; D009885:Ophthalmology / Q000379:methods*; D018903:Photorefractive Keratectomy; D012189:Retrospective Studies; D013666:Tears / Q000378:metabolism*; D016896:Treatment Outcome; D014792:Visual Acuity