Coefficient of friction of ocular surface lubricants for laser in situ keratomileusis.
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.
Lenton
L M
LM
Queensland University of Technology, Brisbane, Australia.
Albietz
J M
JM
D017276:Friction; D020731:Keratomileusis, Laser In Situ; D008153:Lubrication; D008422:Materials Testing; D009883:Ophthalmic Solutions
D009883:Ophthalmic Solutions