title: Comparison of the effects of first and second generation silicone hydrogel contact lens wear on tear film osmolarity.
abstract: OBJECTIVE
  To compare the effects of first and second generation silicone hydrogel (SiH) contact lens wear on tear film osmolarity.
  
  
  METHODS
  The healthy subjects who have never used contact lenses before were enrolled in the study. Tear film osmolarity values of 16 eyes (group 1) who wore first generation SiH contact lenses were compared with those of 18 eyes (group 2) who wore second generation SiH contact lenses after three months follow-up.
  
  
  RESULTS
  Before contact lens wear, tear film osmolarity of groups 1 and 2 were 305.02±49.08 milliosmole (mOsm) and 284.66±30.18mOsm, respectively. After three months of contact lens wear, osmolarity values were found 317.74±60.23mOsm in group 1 and 298.40±37.77mOsm in group 2. Although osmolarity values for both groups of SiH contact lens wear after three months periods were slightly higher than before the contact lens wear, the difference was not statistically significant.
  
  
  CONCLUSIONS
  Contact lens wear may cause evaporation from the tear film and can increase tear film osmolarity leading to symptoms of dry eye disease. In the current study, there is a tendency to increase tear film osmolarity for both groups of SiH contact lens wear, but the difference is not statistically significant.
authors.affiliation: Department of Ophthalmology, Cerrahpasa School of Medicine, Istanbul University, Cerrahpasa, Fatih/Istanbul Istanbul 34098, Turkey.
authors.forename: Guzin
authors.initials: G
authors.lastname: Iskeleli
authors.forename: Yunus
authors.initials: Y
authors.lastname: Karakoc
authors.forename: Ahmet
authors.initials: A
authors.lastname: Ozkok
authors.forename: Ceyhun
authors.initials: C
authors.lastname: Arici
authors.forename: Omer
authors.initials: O
authors.lastname: Ozcan
authors.forename: Osman
authors.initials: O
authors.lastname: Ipcioglu
keywords: contact lens related dry eye; dry eye; silicone hydrogel contact lens; tear film osmolarity