title: Tear secretion following spherical and astigmatic excimer laser photorefractive keratectomy.
abstract: OBJECTIVE
  To evaluate the effect of spherical and astigmatic excimer laser photorefractive keratectomy (PRK and PARK, respectively) on tear secretion.
  
  
  METHODS
  The Vlemma Eye Center, Athens, Greece.
  
  
  METHODS
  Forty-eight eyes of 48 patients had PRK (28 eyes) or PARK (20 eyes) for the correction of myopia and combined myopic astigmatism. The fellow eye served as a control. The mean preoperative spherical equivalent was -3.96 diopters (D) +/- 1.00 (SD) in the PRK eyes (range -2.00 to -6.50 D) and -3.45 +/- 0.50 D in the PARK eyes (range -1.75 to -6.00 D). Attempted correction aimed at emmetropia. Schirmer I and II and tear film breakup time (BUT) tests were performed preoperatively and 1, 3, and 6 months postoperatively. All tests were correlated to the amount of attempted correction.
  
  
  RESULTS
  In the PRK group, the preoperative mean values were Schirmer I, 16.20 mm; Schirmer II, 12.73 mm; and BUT, 16.46 sec. At 1 month, they were 12.23 mm, 8.46 mm, and 13.33 sec, respectively; at 3 months, 13.86 mm, 10.64 mm, and 14.42 sec, respectively; at 6 months, 14.32 mm, 11.32 mm, and 15.36 sec, respectively. In the PARK group, the mean Schirmer I, II, and BUT values were preoperatively 18.52 mm, 14.86 mm, and 17.42 sec, respectively; at 1 month, 14.5 mm, 10.4 mm, and 14.36 sec, respectively; at 3 months, 15.36 mm, 11.81 mm, and 14.72 sec, respectively; and at 6 months, 16.5 mm, 12.15 mm, 16.5 sec, respectively. No correlation to the amount of attempted correction was found. Fellow-eye tests were not affected at any interval.
  
  
  CONCLUSIONS
  In the first 6 months after PRK and PARK, tear secretion test values decreased.
authors.affiliation: Vlemma Eye Institute, Athens, Greece. siganos@vlemma.com
authors.forename: D S
authors.initials: DS
authors.lastname: Siganos
authors.forename: C N
authors.initials: CN
authors.lastname: Popescu
authors.forename: C S
authors.initials: CS
authors.lastname: Siganos
authors.forename: G
authors.initials: G
authors.lastname: Pistola
mesh_terms: D000328:Adult; D001251:Astigmatism / Q000378:metabolism / Q000601:surgery*; D001767:Blinking / Q000502:physiology; D003315:Cornea / Q000294:innervation / Q000378:metabolism / Q000601:surgery*; D005260:Female; D006801:Humans; D007765:Lacrimal Apparatus / Q000378:metabolism; D054018:Lasers, Excimer; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000378:metabolism / Q000601:surgery; D018903:Photorefractive Keratectomy; D011184:Postoperative Period; D011379:Prognosis; D011446:Prospective Studies; D013666:Tears / Q000378:metabolism*