title: Assessment of tear osmolarity and other dry eye parameters in post-LASIK eyes.
abstract: OBJECTIVE
  To assess the tear osmolarity using the TearLab device after laser in situ keratomileusis (LASIK) and to compare the values with those obtained by traditional tear film tests before and after the procedure.
  
  
  METHODS
  Thirty eyes of 15 refractive surgery candidates (5 men and 10 women of mean age: 30.55 ± 11.79 years) were examined. Using a special questionnaire (Ocular Surface Disease Index), subjective dry eye complaints were evaluated, and then, the tear osmolarity was measured with the TearLab system (TearLab Corporation) and conventional dry eye tests were carried out. Examinations were performed preoperatively and at 1, 30, and 60 days after the surgery.
  
  
  RESULTS
  The mean value of tear osmolarity was 303.62 ± 12.29 mOsm/L before the surgery and 303.58 ± 20.14 mOsm/L at 60 days after the treatment (P = 0.69). Mean lid parallel conjunctival folds value was 0.68 ± 0.68 before the procedure and 0.58 ± 0.65 subsequent to surgery (P = 0.25). Meibomian gland dysfunction was not detected. No significant deviation was observed in the values of Schirmer test, corneal staining, tear break-up time, and lid parallel conjunctival folds when compared with postoperatively obtained values during the follow-up period (P > 0.05).
  
  
  CONCLUSIONS
  During LASIK flap creation, intact corneal innervation is damaged, and the ocular surface lacrimal functional unit can be impaired. In our study, no abnormal dry eye test results were observed before or after the procedure. Based on our results, LASIK treatment is safe for dry eye involving the administration of adequate artificial tears for a minimum of 3 months.
authors.affiliation: Orbi-Dent Health and Laser Center, Debrecen, Hungary. zhassan@dote.hu
authors.forename: Ziad
authors.initials: Z
authors.lastname: Hassan
authors.forename: Eszter
authors.initials: E
authors.lastname: Szalai
authors.forename: Andras
authors.initials: A
authors.lastname: Berta
authors.forename: Laszlo
authors.initials: L
authors.lastname: Modis
authors.forename: Gabor
authors.initials: G
authors.lastname: Nemeth
mesh_terms: D000293:Adolescent; D000328:Adult; D003315:Cornea / Q000294:innervation; D003941:Diagnostic Techniques, Ophthalmological; D015352:Dry Eye Syndromes / Q000175:diagnosis / Q000188:drug therapy / Q000601:surgery*; D005260:Female; D006801:Humans; D020731:Keratomileusis, Laser In Situ; D054018:Lasers, Excimer / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009216:Myopia / Q000601:surgery*; D009883:Ophthalmic Solutions / Q000008:administration & dosage; D009994:Osmolar Concentration; D011184:Postoperative Period; D013524:Surgical Flaps; D011795:Surveys and Questionnaires; D013666:Tears / Q000737:chemistry*; D055815:Young Adult
chemical_list: D009883:Ophthalmic Solutions