title: Preoperative characteristics and a potential mechanism of chronic dry eye after LASIK.
abstract: OBJECTIVE
  To determine whether measurable preoperative characteristics predispose patients to chronic dry eye after laser in situ keratomileusis (LASIK).
  
  
  METHODS
  The study consisted of 24 eyes of 24 patients who underwent LASIK. Tear breakup time, Schirmer testing with and without anesthesia, rose bengal staining, central corneal sensitivity, nucleus-to-cytoplasmic ratio, and goblet cell density were evaluated 2 weeks before and 1 week, 3 months, and 9 months after surgery. Patients were classified into two outcome groups, the nondry-eye group (NDEG) and the chronic dry-eye group (CDEG), on the basis of dry eye status 9 months after surgery. The authors tested whether preoperative values of each parameter were associated with the development of chronic dry eye.
  
  
  RESULTS
  All parameters, except rose bengal staining, deteriorated significantly after surgery but returned to preoperative levels within 3 to 9 months. The CDEG had significantly lower preoperative Schirmer test values with and without anesthesia and were delayed in recovery after surgery in goblet cell density, rose bengal staining, Schirmer test values without anesthesia, and tear breakup time. Results of preoperative Schirmer tests without anesthesia positively correlated with tear breakup time 9 months after surgery.
  
  
  CONCLUSIONS
  Preoperative tear volume may affect recovery of the ocular surface after LASIK and may increase the risk for chronic dry eye.
authors.affiliation: Schepens Eye Research Institute, 20 Staniford Street, Boston, MA 02114, USA.
authors.forename: Keiko
authors.initials: K
authors.lastname: Konomi
authors.forename: Li-Li
authors.initials: LL
authors.lastname: Chen
authors.forename: Rachel S
authors.initials: RS
authors.lastname: Tarko
authors.forename: Amy
authors.initials: A
authors.lastname: Scally
authors.forename: Debra A
authors.initials: DA
authors.lastname: Schaumberg
authors.forename: Dimitri
authors.initials: D
authors.lastname: Azar
authors.forename: Darlene A
authors.initials: DA
authors.lastname: Dartt
mesh_terms: D000328:Adult; D002452:Cell Count; D002908:Chronic Disease; D003228:Conjunctiva / Q000473:pathology; D015352:Dry Eye Syndromes / Q000209:etiology*; D005260:Female; D020397:Goblet Cells / Q000473:pathology; D006801:Humans; D020731:Keratomileusis, Laser In Situ / Q000009:adverse effects*; D008297:Male; D012307:Risk Factors; D013666:Tears / Q000378:metabolism; D013997:Time Factors