Abstract
Purpose :
The purpose of this study is to examine the influence of the tear supply and drainage on the tear dynamics. During a blink, tear fluid supplied from the lacrimal gland is distributed from the upper meniscus region onto the ocular surface to form a stable tear film. Because the current state-of-the-art instrumentation does not yet have the capability to estimate the tear film thickness over the entire front of the eye, especially near the lids during the upstroke and downstroke, it is not fully understood how the tear supply impacts the tear film formation, and thus subsequent tear film thinning during the interblink.
Methods :
In this study, we explore a mathematical model to simulate the tear film thickness on a realistic moving eye-shaped domain. The domain is described by curves fit to lid margins in a video of a blinking eye. The motion of the tear film is influenced by viscosity and surface tension. We examine how different models of tear supply and drainage, linked to lid motion and lid speed, affect the tear formulation and subsequent tear film breakup times.
Results :
We find the formation of the tear film during the upstroke and downstroke is sensitive to the lid motion and the tear supply from under lids. During relaxation, the eye shape influences the continued formation of the black line regions. Our results will be compared and contrasted with prior one-dimensional modeling efforts as well as experimental observations.
Conclusions :
A simulation of the tear film dynamics on an eye-shaped domain was created and the influence of the tear supply and drainage on the tear film formation during a blink was studied. Our model provides insight into the tear film dynamics near the upper lid during a blink, a region difficult to image.
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.