Cure for Dry eye through Computer Simulated Tear Maps

Dry eye, a burning condition that can impair vision and damage the cornea, in some cases, affects millions of people around the world, particularly older individuals.

Yet a new treatment that uses computer simulations to map the tears that move across the eye's surface may provide better treatment for the health issue, according to researchers from the Rochester Institute of Technology's School of Mathematical Sciences.

"Tear Film Dynamic with Evaporation, Wetting and Time Dependent Flux boundary Condition on an Eye-shaped Domain," said Kara Maki, assistant professor at the institute, via a press release. "We're hoping if we can understand better the basic dynamics of the tear film, then we can start to understand what goes wrong if you have dry eye and start to think about potential cures by studying simulations."

According to the National Eye Institute, women are predominantly affected by this condition with more than 3 million diagnosed with dry eye due to hormonal changes associated with menopause.

Though eye drops can temporarily relieve the issue, Maki said she believes that to understand the condition better, the physics and chemistry of tears must be assessed. Tear film creates a layer of water sandwiched between an oily layer of lipids on the outside to prevent evaporation, while the eye's inner mucous layer spreads the water over the eye.

Based on this information, she came up with a mathematical model to simulate the direction tear film travels as it enters the eye from the lacrimal glands. With the help of the software program Overture, she helped make the flow of tears on the surface of an open eye, moving from the upper corner and draining through the ducts at the opposite corner. 

"One thing we were able to find is that when your eyes are open, the tears get thin right along the edge of the eye, and that is referred to as the 'black line,'" Maki said, via the release. "That has been seen clinically and can be reproduced in our simulations."

"The nice thing about having a model is that you can make unrealistic things happen," Maki added. "For example, we can flood the eye and see where the tears go. Or we can look at what happens when the drainage holes are plugged. Where does the fluid go? You can start to explore these things in a safe way."

More information regarding the findings can be seen via the journal Physics of Fluid.