title: Coefficient of friction of ocular surface lubricants for laser in situ keratomileusis.
abstract: OBJECTIVE
  The coefficient of friction was empirically derived for a series of commercially available ophthalmic lubricants having potential use during laser in situ keratomileusis (LASIK).
  
  
  METHODS
  Measurements were obtained using a modified tensile testing machine. Solutions tested included the artificial tear supplements Polytears-free, Bion Tears, Genteal, Refresh, Cellufresh, Celluvisc, Theratears, and Viscotears gel; and balanced salt solution (BSS).
  
  
  RESULTS
  Viscotears carbomer gel had a significantly lower mean coefficient of friction compared to other ophthalmic lubricants tested (P=.002) and the dry plate (P=.005). Addition of 0.1 ml of BSS to 0.025 ml of Celluvisc significantly reduced the coefficent of friction of Celluvisc (P=.01). Polytears, Bion Tears, Genteal, Refresh, Celluvisc, Theratears, and BSS had coefficients of friction significantly higher than that of the dry plate.
  
  
  CONCLUSIONS
  A range of values were obtained for the coefficient of the ophthalmic lubricants tested. Viscotears gel (0.1 ml), and Celluvisc (0.025 ml) + BSS (0.1 ml) had coefficients of friction significantly lower than that of the dry plate.
authors.affiliation: Queensland University of Technology, Brisbane, Australia.
authors.forename: L M
authors.initials: LM
authors.lastname: Lenton
authors.forename: J M
authors.initials: JM
authors.lastname: Albietz
mesh_terms: D017276:Friction; D020731:Keratomileusis, Laser In Situ; D008153:Lubrication; D008422:Materials Testing; D009883:Ophthalmic Solutions
chemical_list: D009883:Ophthalmic Solutions