A contact lens with a built-in sensor could help determine which glaucoma patients have a higher risk of disease progression. Researchers from Columbia University Medical Center found certain patterns of electrical signals emitted from the "smart" contact lenses correlate with a faster rate of glaucoma progression, according to the study published in Ophthalmology.

Glaucoma remains a leading cause of blindness. Intraocular pressure (IOP) tests yield a single snapshot in time and are impractical to perform at night when eye pressure typically rises. With the advent of smart contact lenses that monitor patients continuously, scientists are hoping to solve that problem.

Researchers at Columbia tested the lenses on 40 patients between ages 40 and 89 undergoing treatment for open-angle glaucoma, the most common form of the disease. Over two years, scientists performed at least eight standard visual field tests on these patients. Half were classified as having slow disease progression while the other 20 had fast disease progression.

The patients then wore a smart contact lens for 24 hours, including overnight as they slept. The sensor on the lens detects changes in lens curvature. As eye pressure fluctuates, the curve changes, generating an electrical signal sent to a wireless device that records the signals. Similar to how an electrocardiogram shows a heartbeat, the profile of signals from the smart lens indirectly shows eye pressure changes over time.

Investigators found that patients with steeper spikes recorded overnight and a greater number of peaks in their signal profile overall tended to have faster glaucoma progression. This information provides more insight into glaucoma and also a blueprint for deciphering the signals from this new wearable technology, meaning clinicians can better estimate the risk of progression by looking at a readout from the smart lens. The findings could also have implications when using the lenses to evaluate glaucoma treatments.  

"What we see in these measurements is a signature that indicates which glaucoma patients will get worse and which are relatively stable, which you can't do with a one-time eye pressure measurement," said associate professor of ophthalmology at Columbia University Medical Center and study author Gustavo De Moraes. "This could be very useful if you want to know whether a new medication is working for a patient. You can see how their eye is reacting to the therapy in a much more meaningful way."