A new microfluidic contact lens prototype developed by researchers from the UCLA Terasaki Institute for Biomedical Innovation (TIBI) is targeting the prevention of contact lens-induced dry eye (CLIDE).
I need a refresher on CLIDE.
CLIDE arises from an insufficient flow of tears from the outer surface of a contact lens to the surface located behind the lens, inducing signs and symptoms of ocular surface dryness. This can cause tear volume reduction, tear film instability, an increase in tear osmolarity, ocular discomfort, and visual disturbances.
What was the researchers’ goal?
They sought to develop a contact lens using microchannels that could transport the tear flow of the pre-lens tear film (PrLTF) to the post-lens ocular surface by using normal eye blinking in order to prevent eye dryness. (via)
Now tell me about this prototype
The lens mold was created from a silicone polymer mixture, which made for an easy removal of the lens cast from it via gently bending the mold, and required a 12-hour, hot water soak in order to remove the lens.
The prototype featured high-quality, smooth microchannels, a thinner lens, and reservoirs (created using a custom device) at the ends of each microchannel for liquid flow. A capping lens layer was added using water-soluble glue. (via)
How was it tested?
The prototype lenses underwent several in vitro experiments using a device that mimicked a human eye blink. The device was embedded within the lens to generate tear flow (via artificial eyelid pressure).
Did it work?
The scientists found that microchannels with square cross-sections arranged on the lens surface in a circular pattern allowed for the ideal tear flow.
Is it ready for primetime?
Not just yet. The researchers successfully achieved a proof-of-concept validation for the prototype lens in leading tear flow from the lens surface to the underside and, as a result, preventing dry eye.
However, they recommended further experimentation to test the microfluidic prototype lenses in patients and in animal models.