Scientists claim that a 'Smart' contact lens might assist with treating a leading cause of blindness

Scientists claim that a 'Smart' contact lens might assist with treating a leading cause of blindness ...

A flexible contact lens that senses eye pressure and releasees a medication on-demand might assist treat glaucoma, the second major worldwide cause of blindness.

The compact wireless device, which has been designed and tested in pig and rabbit eyes so far, appears to detect and reduce increased eye pressure, one of the usual causes of glaucoma.

Glaucoma is a broad term for a spectrum of eye diseases, where damage to the optic nerve, which transmits visual information to the brain, causes irreversible vision loss and blindness in millions of people worldwide.

Where this new research opens new doors, is in the development of a computer capable of detecting eye pressure changes and reasserting therapeutic medications as soon as possible.

Recent efforts to develop smart contact lenses have focused on understanding pressure fluctuations in the eyes or delivering a medication, but not both, and eye drops, laser therapy, and eye surgery are usually required to reduce eye pressure.

While it sounds a lot of fun, keep in mind that as scientists continue to experiment with nifty methods for treating eye diseases, early detection of glaucoma and timely treatment are vital.

"So far as glaucoma has been detected, treatment may prevent or mitigate its deterioration in the majority of cases," says Jaimie Steinmetz, a research scientist at the Washington-based Institute for Health Metrics and Evaluation, and his colleagues in 2020 when contemplating the global consequences.

Because peripheral vision is the first to go, and devices used to diagnose the condition only provide snapshot measurements of intraocular pressure, which fluctuates with activity and sleep-wake cycles, glaucoma is usually difficult to detect.

"Details of improving surveillance systems, highlighting the danger among family members of cases, and the effectiveness of care after treatment," Steinmetz and his co-authors said.

Contact lenses that stand snug against the eye have a great potential for assisting with eye conditions. However, incorporating electrical circuits and sensors into small, flexible, curved, and ultra-thin contact lenses poses a difficult engineering challenge.

For something like this to be successful, it must be sufficiently sensitive to detect pressure fluctuations and release precise amounts of medication on demand, all without blocking vision and irritant the eyes.

"It''s very difficult to make a complex theranostic system, fabricated by multi-modules on a contact lens," Cheng Yang, an electrical engineer from Sun Yat-Sen University, writes in his study.

It appears that Yang and his colleagues have made progress at least in designing a prototype lens that has multiple sensors embedded in it to avoid eye irritation and a unique laser-cut snowflake design.

It''s designed to treat acute angle-closure glaucoma, a less common form of glaucoma that may occur with a sudden or gradual build-up of fluid pressure inside the eyes.

According to the authors, the double-layer lens is coated with an anti-glaucoma medication, brimonidine, and is sandwiched in an ultra-thin air film in between. This air film connects into a cantilevered electrical circuit which detects intraocular pressure when the air pocket is compressed by outward pressure from the eye.

If and when eye pressure is high, the wireless system initiates the release of brimonidine, which flows from the underside of the lens across the cornea into the eye, which is then pushed along by an electrical current in a process known as iontophoresis.

"The double-layer lens design allowed a compact structure to accommodate multiple electronic modulus positioned in the rim area of the contact lens," indicating that it shouldn''t hinder wearers'' perceptions, according to Yang and colleagues.

So far, however, the device has only been tested on pig eyeballs and live rabbits, so further research is required before the lens may begin to develop clinical tests in humans.

For the time being, researchers have claimed that their device can detect intralocular pressure, deliver anti-glaucoma medications via iontophoresis, and "rapidly reduce" eye pressure, as it has been previously described.

In these experiments, rabbit eye pressure also remained low and did not rebound as it did when eye drops of brimonidine were administered as a control medication, thus it looks a little promising.

"This intelligent system provides promising methodologies that might be expanded to other ophthalmic diseases," Yang and colleagues write.

Researchers say their manufacturing methods are compatible with the high-scale and cost-effective manufacturing techniques currently used to make computer circuit boards, so this device may be relatively inexpensive.

Nature will have to keep an eye on what future research will reveal.

Nature Communications has published this research.

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