Revolutionary implant for dry AMD - your questions answered

News broke last month of the positive results from a revolutionary new implant which has enabled people with dry age-related macular degeneration to read letters and numbers again.

The PRIMA System is an implantable that works with a specialised set of glasses which convert light into signals that healthy retinal cells can send to the brain.

The clinical trial, published in the New England Journal of Medicine, showed 84% of participants were able to read letters, numbers. All the participants in this trial had lost the central vision of the eye being tested, leaving only limited peripheral vision.

Mahi Muqit, senior vitreoretinal consultant at Moorfields Eye Hospital and NIHR research investigator, joined our My Macular and Me webinar in November to answer your questions on the device.

How practical is this as a device to wear on a daily basis?

Many wearable devices have a benefit, but can be quite bulky and impractical. Mahi said throughout the clinical trials they have been consulting with patients on the look and feel of the device.

“We're constantly getting feedback from all of the patients who are implanted about their experience of using the device, wearing the device, what could be better? What's bothering them? Is it the size of the glass, the fit of the glasses.”

Mahi highlight that the company had listened to feedback to make the device more practical so it can be worn outside the house. They are currently looking at some new designs.

He added: “They'll look like a pair of kind of flashy sunglasses that you can just put on. There's no cables, there's no kind of camera sticking out. Everything is integrated into the lens. So essentially our patients could just go outside, lift out a pair of glasses, pop them on.”

Are there further trials happening? Is it possible to get on a trial?

This particular trial is not currently recruiting patients and those who have been involved are being monitored. Mahi explained they were working with existing patients to make improvements to the device.

“There's new upgrades to the software, looking at other ways of looking at how the device works, looking to see if they can see things better,” he said.

He also highlighted new trials planned outside of the UK for other inherited conditions such as retinitis pigmentosa, Stargardt disease.

Why is this just being implanted in patients with dry AMD and not wet AMD?

“With wet AMD, it's a completely different condition,” Mahi said.

He explained how in wet AMD one of the layers called retinal pigment epithelium starts to wear out. He added: “It's like wearing out the carpet, really. And then the floorboards start to wear out and suddenly you get these blood vessels growing up through them start leaking fluid, you get blood and that particular space.”

Mahi said this can cause inflammation, scarring, and small damaged areas under the retina. He said trying to place a device in that area while the disease is or has been active, could cause the condition to flare up again. Because of this risk, the device isn’t considered safe or suitable for people who currently have wet AMD.

How long until the device is widely available?

Mahi said the company has started the official safety and quality checks needed for medical devices in Europe. This process began a few months ago, after the Safety Board agreed the trial results looked good. These checks usually take six to nine months and once the device passes, the company can then apply to different countries to get permission for its use.

He added: “It takes some time and certainly we're probably looking at least two years minimum before even trying to get this in the UK.”

Mahi also touched upon the company’s plans to try and make the device available under the NHS. He highlighted how other devices have been unsuccessful in the past but described the PRIMA system as ‘the first one of its kind’

He said: “There has been other devices, but they didn't really give meaningful vision. But this is the first one of its kind, so I think there'll be different types of discussions going on.”

What can people read with the device?

Mahi explained: “It isn't just a kind of case of putting on the glasses and suddenly reading a book. The actual pocket processor the patient wears has a few functions, such as contrast, brightness and actually zoom. So that's quite a crucial thing to remember, is that you have to use the zoom function to really get good clarity of your letter recognition, number recognition and reading ability.”

He said: “It has different levels of zoom that the patients can use depending on how far away the text is, how small they want to see.”

Sharing an example, he added: “We had some patients in other countries, such as France, Germany, who are sort of wandering into a train station or bus station and obviously they stop. They then focus on signage.

“And then they can start to zoom in on those particular areas and actually to read what's on it. So, they can read the names of the stations, platform number.”

Is it possible to recognise faces with this device?

“So that's something which we've, we've been exploring with this particular system,” said Mahi.

He explained how currently you can't recognise faces but it is something that us being looked into.

He added: “This is something again which hopefully by the time it comes to markets the software will have been refined even further to enable some form of facial recognition. Again, it's completely hypothetical, but it is something which this is all to do with again listening to the patients, trying to expand the functionality of the device. But in a few years’ time we may be speaking about other aspects of vision.”

How could this technology evolve in the future?

“I think there will be other devices around, which is good for patients because not every patient is going to be suitable for one device, as we know, with any therapy,” said Mahi.

“I think in a couple of years you may have other emerging devices coming along which hopefully have similar effects.  

He added: “I think in the future there's going to be other types of prosthetic devices coming along and there's many in the pipeline at the moment which look very promising.”

Mahi said when he started this work 10 years ago devices got a negative reputation as it wasn’t giving patients enough functional vision. But he said the PRIMA device had been designed with patients in mind.

 He said: “There’s now a whole new kind of focus on actually doing the research, engaging patients, designing things which are specifically for conditions. So, I think it's all going to change in the next five years.”

To hear more about the new PRIMA system and how it works, listen again to