Effect of viscosity on tear drainage and ocular residence time.

摘要: Purpose. An increase in residence time of dry eye medications including artificial tears will likely enhance therapeutic benefits. The drainage rates and the drops depend on viscosity instilled fluids. However, a quantitative understanding dependence is lacking. current study aims to develop mathematical model for Newtonian fluids also power-law non-Newtonian different viscosities. Methods. This an extension our previous tear drainage. modified describe with viscosities higher than rheological parameters obtained from fitting experimental data literature. rate through canaliculi was derived incorporated into mass balance calculate transients total solute quantity ocular bioavailability drugs. Results. For fluids, increasing does not affect unless exceeds critical value about 4.4 cp. has maximum impact around 100 trends are similar shear thinning power law quantity, agrees at least qualitatively studies. Conclusions. A been developed canaliculi. can quantitatively explain observations effect surface. helpful mechanism fluid surface improving design treatments.