Glaucoma, eye pressure monitoring via implanted sensor

Date: Jun-17-2014Monitoring of pressure inside the eye is key to early detection of glaucoma, a group of

conditions that damage the optic nerve, and a leading cause of blindness in the US where it

affects around 2.2 million people, according to the Glaucoma Research Foundation. Now engineers at

the University of Washington in Seattle are designing a sensor that can be fixed permanently

inside the eye and continuously monitor hard-to-measure changes in eye pressure.

The team foresees a future - not too far away - where the human eye encapsulates its own

high-tech information center, keeping a close watch on important health changes and issuing

warnings of when it is time to see the eye doctor.

The prototype the engineers are working on would be implanted along with an artificial lens when a

patient has cataract surgery. Once in place, the

sensor detects pressure changes in the eye immediately, and transmits the data wirelessly using

radio frequency waves.

Eye pressure fluctuates over the day, much in the same way as blood pressure. If the pressure

inside the eye gets too high it can begin to damage the optic nerve - often with no pain or

warning sign. Increased intra-ocular pressure is the main factor in glaucoma.

The team foresees a future where the human eye encapsulates its own high-tech information center, keeping a close watch on important health changes.

The engineers describe their new device - which incorporates a pressure sensor and radio chip,

and an antenna that circles the perimeter of the artificial lens - in a paper published in the

Journal of Micromechanics and Microengineering. Patents on the initial prototype design

have already been filed.

The device itself just has to handle raw data. The heavy computational work can then be done in

another device that receives the data - such as a handheld device or possibly even built into a

smartphone, says the team.

Senior author Karl Böhringer, a professor of electrical engineering and bioengineering, says

no one has ever embedded electronics inside the lens of the eye before, and their prototype shows

it is possible in principle. The added benefit, he explains is:

"If you can fit this sensor device into an intraocular lens implant during cataract surgery, it

won't require any further surgery for patients."

Cataracts and glaucoma affect a similar aging population so it makes sense to pair the

procedures, says the team.

Glaucoma damage is often spotted too late

When they started their work the researchers were looking for an easy way to measure eye

pressure. At present there are two ways to do this, and both require a visit the ophthalmologist.

This means patients at risk for glaucoma get to have their eye pressure measured a few times a

year, at the most.

But if the ophthalmologist could insert a pressure monitor directly into the eye, then pressure

would be tracked continuously. This could be done during cataract surgery - a procedure undergone

by some 3 to 4 million Americans every year to correct blurred vision or glare caused by a hazy

lens.

Co-developer Tueng Shen, a professor of ophthalmology, says they are working on making the

device simple and reliable, and well-suited for clinical use, and adds:

"We want every surgeon who does cataract surgeries to be able to use this."

She says often the damage to eyesight is noticed too late for treatments to be effective. Also,

if medications are given, there is no effective way to monitor the results. She adds that there is a need for

techniques to diagnose glaucoma earlier and ensure patients are on the correct treatment plan.

The current prototype is too big to fit in a lens, but the team is confident it can downscale

the technology. The engineers have already tested that it works when embedded in the same flexible

silicon that artificial lenses are made of.

The Coulter Foundation and the University of Washington funded the research.

In February 2014, Medical News Today reported how researchers from the University of

California, Los Angeles have developed a nanodiamond-embedded contact lens that delivers glaucoma

drugs more effectively to improve the treatment of the condition.

Written by Catharine Paddock PhD

View all articles written by Catharine, or follow Catharine on:

Courtesy: Medical News Today Note: Any medical information available in this news section is not intended as a substitute for informed medical advice and you should not take any action before consulting with a health care professional.