title: Changes in tear flow and tear film stability after photorefractive keratectomy.
abstract: OBJECTIVE
  To investigate the changes in tear flow and tear film stability after photorefractive keratectomy (PRK) for myopia.
  
  
  METHODS
  One eye of 32 patients underwent unilateral PRK procedure for the correction of myopia ranging from -1.50 to -6.00 diopters (D) (mean -3.65 +/- 1.55 D). Schirmer test values and break-up time (BUT) scores were measured 6 weeks after the PRK procedure. Unoperated, contralateral eyes were used as control eyes for each patient. The Schirmer test scores and BUT values were statistically analyzed using independent t test.
  
  
  RESULTS
  The mean Schirmer test value was 14.45 +/- 7.79 mm in the operated eyes. It was 28.83 +/- 5.89 in the control eyes. The decrease in Schirmer test value was statistically significant (t = 8.28, p = 0.0001). The mean BUT scores were 13.19 +/- 5.09 s in the operated eyes and 27.83 +/- 9.31 s in the control eyes. The decrease was statistically significant (t = 7.86, p = 0.0001).
  
  
  CONCLUSIONS
  PRK causes a decrease in tear flow and tear film stability that is probably caused by decreased corneal sensation after PRK.
authors.affiliation: Istanbul University, Eye Research Center, Turkey. aozdamar@iris.com.tr
authors.forename: A
authors.initials: A
authors.lastname: Ozdamar
authors.forename: C
authors.initials: C
authors.lastname: Aras
authors.forename: N
authors.initials: N
authors.lastname: Karakas
authors.forename: B
authors.initials: B
authors.lastname: Sener
authors.forename: M
authors.initials: M
authors.lastname: Karacorlu
mesh_terms: D000328:Adult; D003315:Cornea / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D054018:Lasers, Excimer; D008297:Male; D009216:Myopia / Q000503:physiopathology / Q000601:surgery*; D018903:Photorefractive Keratectomy; D011184:Postoperative Period; D011379:Prognosis; D011446:Prospective Studies; D013500:Surface Tension; D013666:Tears / Q000502:physiology*