Featuring a dual layer, the smart lenses are able to detect an increase in intraocular pressure through sensors and release an anti-glaucoma drug to relieve the pressure and thus prevent blindness.
Contact lenses as we know them today are destined to evolve into something more elaborate. Moreover, some types of lenses are already today more than just a device for immediately correcting vision. Worn overnight, they can improve vision for several hours. But thanks to scientific advances, they could go even further and treat certain eye diseases, including glaucoma, the second leading cause of blindness in the world.
Chinese researchers have succeeded in developing a new type of lens capable of detecting increased eye pressure, one of the common causes of glaucoma, and releasing a drug to lower the pressure. So far, the device has only been tested on pig and rabbit eyes, but the results are encouraging.
Help millions of people around the world
Developing a way to treat glaucoma would prevent millions of people from losing their sight – partially or not. This disease, which in reality encompasses several forms, results from excessive pressure in the eye which has damaged the optic nerve, responsible for relaying visual information to the brain.
Many studies attempt to find a solution to combat this increased pressure inside the eye. Some have already considered the possibility of using smart lenses which could either detect a rise in pressure or deliver a drug, but not both. This is where the study by Chinese researchers stands out since their device combines the two aspects.
A serious technical challenge
Integrating electrical circuits and sensors into flexible, curved and thin contact lenses is a real technical challenge. The device must be sensitive enough to detect changes in pressure and release precise amounts of medication, without blocking vision or irritating the eye, stresses Science Alert.
“It is very difficult to install a complex theranostic system consisting of several modules on a contact lens”, write the researchers in their article. They still managed to manufacture a prototype integrating several sensors that does not irritate the eye of its wearer.
The device was developed to treat acute angle-closure glaucoma, an uncommon form that results in a sudden or gradual buildup of fluid pressure in the eye.
How it works ?
The lens is coated with an anti-glaucoma drug and sandwiches an ultra-thin film of air. The electrical circuit to which the air pocket is connected detects changes in intraocular pressure depending on whether the pocket is compressed or not. When the pressure reaches a certain level, the wireless system triggers the release of anti-glaucoma medication.
“The dual-layer lens design allowed for a compact structure to accommodate multiple electronic modules positioned in the contact lens edge region,” meaning it shouldn’t block wearers’ view, write Researchers.
Early results in animal eyeballs were encouraging, but more research is needed before the lenses are used in humans. The researchers also believe that their design could be extended to the treatment of other ophthalmic diseases.
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