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Scientists have developed a contact lens that can release a medicine if it senses excessive pressure within the eye, which they believe will help cure glaucoma.
Glaucoma is a group of eye conditions that damage the optic nerve, the health of which is vital for good vision. This damage is often caused by abnormally high pressure in the eye.
The most prevalent form of the condition, known as primary open-angle glaucoma, is believed to impact around 10% of those over the age of 75. Increased pressure within the eye, usually due to an accumulation of fluid, causes this type.
Researchers in China at the Sun Yat-sen University have created a contact lens that can detect an increase in intraocular pressure and release an anti-glaucoma medicine if the pressure rises over a set threshold.
The team describes how they developed the gadget using an upper and lower lens, with a snowflake-shaped pressure sensor and wireless power transfer device sandwiched between them around the rim of the lenses, in the journal Nature Communications. The arrangement gives the impression that the wearer has golden irises. The design, however, allows for the essential components to be integrated with the device without obscuring the wearer’s view or irritating the eye, according to the scientists.
The distance between the upper and lower lenses narrows as the pressure inside the eye rises. The pressure sensor uses a cantilever to detect this. The sensor then transmits a signal to the wireless system, which causes an anti-glaucoma medicine, brimonidine, to be released from a hydrogel linked to an electrode and cross the cornea of the eye. Brimonidine works by lowering the pressure inside the eye.
The contact lenses have been tested on pigs’ eyes and on the eyes of living rabbits, according to the report, but human trials have yet to be conducted.
The lenses are not just soft and less intrusive, but also battery-free, according to the researchers, who believe the technology might be broadened to aid with other eye problems.
Prof Zubair Ahmed of the University of Birmingham’s Institute of Inflammation and Ageing, who was not involved in the research, told the Guardian, that the findings were potentially extremely fascinating, adding that an increase in intraocular pressure was a serious concern for most individuals with glaucoma.
“Here, the researchers have developed a minimally invasive contact lens that can detect these changes in pressure within the eye to provide real-time monitoring, but the contact lens can also respond by allowing on-demand drug delivery directly to the eye,” he said.
“The materials required to create such contact lenses are inexpensive and soon could be mass-produced,” he added.