Could This Eye Implant Restore Vision? What You Should Know About the PRIMA Device

What causes AMD?

AMD is a progressive, multifactorial eye disease that becomes more common as we get older. The cause of it is not clear, but we know that genetics play a role because it runs in families. Environmental factors, such as high cholesterol, hypertension, and diabetes, also play a role.

What is the typical treatment approach for AMD?

It depends on the stage of AMD. For intermediate AMD, it’s usually preventive measures like wearing UV protection when in the sun, eating a Mediterranean diet, and taking AREDS 2 dietary supplements to help slow progression.

With advanced dry AMD, there has historically been no treatment option. Recently, the U.S. Food and Drug Administration approved two injections that aim to slow down the disease, but there aren’t options for reversing damage the disease has caused. The PRIMA implant is a good start, but we’re not sure if it’s a game changer quite yet.

Though the PRIMA implant has gotten media attention, it is still experimental. Can you give an overview of current research?

The PRIMA implant was studied in Europe with AMD patients, known as the PRIMAvera study. The results of that study (which assessed 32 patients a year after getting the implant) generated news features and a lot of excitement — mostly around the fact that for the first time ever, there was reported vision improvement. For geographic atrophy, there has never been a fix before. Patients just lost vision, and that was the end of the story, so this created a lot of buzz.

Currently, this device is being evaluated by the European version of the FDA, but it’s not been approved yet in Europe for use. There have been no clinical trials of the device in the U.S.

The PRIMAvera study reported an improvement in patients’ vision, but you explain there are some notable nuances. What were some of your takeaways?

The implant can zoom in on an image, and the glasses have a processor that gives patients some control over both the zoom and brightness levels of what they’re seeing. The device can zoom in about 12 times on an image, which is one of the ways that the study reported a betterment of patients’ vision. The question they didn’t answer in the study is whether there is a difference between that and giving patients a 12x magnifier.

When my patients saw the study, they thought it meant they’d be able to read again, but that’s not necessarily true. The implant device only supports a certain number of pixels in an image, meaning your “best” vision would be around 20/400. The baseline vision of patients before the surgery was roughly around that range already. So, when you consider that the best the implant can do is 20/400 with the ability to see smaller letters only with zoom, it’s not a huge game changer for a lot of my patients.

As a clinician, I’m a bit wary on whether this was meaningful to patients. I noticed that at the start of the study, patients were asked about their reading capacity, mobility, emotional well-being, and overall function. At the end of the study, about a year after patients got the implant, many did not report improvement — they didn’t feel like their life was much better, especially with reading and mobility. In my view, if it’s not meaningful to you on a day-to-day basis, then you might not need it, especially considering it's a surgical implantation.

What do you see as the benefits of this study?

The PRIMAvera study was a good first step because it showed that the technology is something the eye can tolerate. Overall, the body did not reject the device and there were no severe complications.

Now, investigators can study devices that have a much higher number of pixels, as that could result in a more significant improvement in vision for patients.

Given how experimental PRIMA still is, what steps must occur before you can consider this an option for your patients?

It would need to go through several studies, including a clinical trial in the U.S. First, a safety study is needed, and then, a study that shows clinical benefit for patients. The FDA would also need to review and approve the device. It can take many years for devices like this to come onto the market.

Overall, there is a lot of exciting progress with this implant, and the study suggests that it’s a safe device that we can hopefully improve upon. There are also other upcoming and emerging treatments to look out for. At CU Anschutz, we have faculty who are working to uncover whether stem cells can help restore lost vision in patients with AMD. While there aren’t options ready today, there is more to follow.