title: Changes in corneal Langerhans cell density during the first few hours of contact lens wear.
abstract: OBJECTIVE
  To determine the impact of contact lens wear on Langerhans cell density (LCD) in the central cornea over an 8h period.
  
  
  METHODS
  Ten participants wore a hydrogel lens in one eye (the experimental eye) for 8h. The contralateral non-lens-wearing eye served as a control. The central cornea of each eye was examined at the level of the subbasal nerve plexus using a laser scanning corneal confocal microscope, at baseline (prior to lens wear), then every 2h for 8h.
  
  
  RESULTS
  At baseline, LCD was 18±19 and 20±19 cells/mm(2) in the experimental and control eyes, respectively. In the experimental eye, LCD increased to 36±32 cells/mm(2) after 2h and then decreased gradually to 30±31 cells/mm(2) after 6h. LCD was greater in the experimental eye than the control eye at the 2, 4, 6 and 8h time points (p<0.05). LCD remained constant in the control eye throughout the 8h experiment.
  
  
  CONCLUSIONS
  LCD increases two-fold within the first 2h of lens wear, indicating a rapid, sub-clinical inflammatory response to uncomplicated lens wear.
authors.affiliation: Institute of Health and Biomedical Innovation, and School of Optometry and Vision Science, Queensland University of Technology, Kelvin Grove, Australia.
authors.forename: Yahya
authors.initials: Y
authors.lastname: Alzahrani
authors.affiliation: Institute of Health and Biomedical Innovation, and School of Optometry and Vision Science, Queensland University of Technology, Kelvin Grove, Australia.
authors.forename: Nicola
authors.initials: N
authors.lastname: Pritchard
authors.affiliation: Institute of Health and Biomedical Innovation, and School of Optometry and Vision Science, Queensland University of Technology, Kelvin Grove, Australia. Electronic address: n.efron@qut.edu.au.
authors.forename: Nathan
authors.initials: N
authors.lastname: Efron
mesh_terms: D000328:Adult; D058070:Asymptomatic Diseases; D002452:Cell Count / Q000379:methods; D003261:Contact Lenses / Q000009:adverse effects*; D003315:Cornea / Q000276:immunology / Q000473:pathology*; D005260:Female; D006801:Humans; D007634:Keratitis / Q000209:etiology* / Q000276:immunology / Q000473:pathology*; D007801:Langerhans Cells / Q000473:pathology*; D008297:Male; D018613:Microscopy, Confocal / Q000379:methods*; D016037:Single-Blind Method; D016896:Treatment Outcome; D055815:Young Adult
keywords: Contact lens; Cornea; Langerhans cells; Laser scanning confocal microscopy