A contact lens that can release a drug if it senses high pressure in the eye has been created by scientists who say it could help treat glaucoma.
Glaucoma is an eye disease that damages the optic nerve and can lead to blindness if left untreated.
According to the charity Glaucoma UK, the most common form of the disease, known as primary open-angle glaucoma, is thought to affect almost 10% of people aged over 75. This form is usually caused by increased pressure in the eye, usually as a result of fluid buildup.
Researchers in China have revealed they have developed a contact lens that can detect increased pressure in the eye and release an anti-glaucoma drug if the pressure rises above a certain level.
Writing in the journal Nature Communications, the team describe how they created the device using a top and bottom lens, with a snowflake-shaped pressure sensor and a wireless power transfer device. sandwiched between them around the edge of the lenses. The arrangement seems to give the effect that the wearer has golden irises. However, the team says the design allows the necessary components to be included in the device without blocking the wearer’s view or irritating the eye.
As the pressure inside the eye increases, the gap between the upper and lower lenses decreases. This is detected by the pressure sensor by means of an overhang. The sensor then sends a signal to the wireless system which then triggers the release of an anti-glaucoma drug, from a hydrogel attached to an electrode, and allows it to pass through the cornea of the eye. The medicine, brimonidine, works to reduce the pressure in the eye.
The study reveals that the contact lenses have so far been tested in the eyes of pigs and in the eyes of live rabbits – albeit with smaller sized lenses – although trials have not yet been conducted. made in humans.
The researchers note that the lenses are not only soft and minimally invasive, but also battery-free, adding that the approach could be extended to help fight other eye diseases.
Professor Zubair Ahmed from the Institute of Inflammation and Aging at the University of Birmingham, who was not involved in the work, said the research was potentially very exciting, adding that increased pressure in the eye was a significant problem for most people with glaucoma. .
“Here, researchers have developed a minimally invasive contact lens that can sense these pressure changes in the eye to provide real-time monitoring, but the contact lens can also respond by enabling on-demand drug delivery. straight to the eye,” he said. mentioned.
There was potential to further develop the technology, he added. “We can now imagine that a person with glaucoma wearing these contact lenses will not only receive real-time information about the pressures inside the eye, since the contact lens has built-in wireless capability and can easily communicate with an app on your smartphone, but also receive, for example, medication to relieve pressure when needed.
“The materials needed to create such contact lenses are inexpensive and could soon be mass-produced,” he added.