Frank Holz, M.D., is a world-renowned authority in retinal diseases and a central figure in the global effort to treat macular degeneration. As Professor and Chairman of the Department of Ophthalmology at the University of Bonn, Germany, Dr. Holz has spent decades advancing the clinical understanding of retinal conditions.
Dr. Holz served as the Scientific Coordinator and lead author of the PRIMA clinical trial. In this role, he directed the clinical evaluation of the PRIMA system’s efficacy in restoring vision to patients with central vision loss. The study results were recently published in The New England Journal of Medicine (NEJM). This peer-reviewed publication details the primary outcomes of the trial, reporting the safety and functional improvements observed in patients implanted with the device.
This conversation is the first in a series featuring the principal investigators behind the PRIMA clinical trial. We spoke with Dr. Holz about the significance of these findings and the new reality of restoring sight to clinical trial patients who had been functionally blind.
Q: The PRIMA clinical trial results are being described as a major breakthrough. Why is this study so significant for the field of vision restoration?
It’s the first ever therapeutic approach that has led to an improvement in visual function in this group of patients in clinical trials. To put this in perspective, late-stage atrophic age-related macular degeneration is really a dismal disease that leads to irreversible loss of central vision. Patients are no longer capable of reading, no longer capable of driving a car, watching TV, or even recognizing faces, so their quality of life is affected to a large extent.
And now it’s been demonstrated in clinical trials that through the PRIMA system, these patients with this disease who had lost their central vision completely, can again read letters, numbers and also even books.
Q: We’ve seen other approaches to treating AMD. How does PRIMA compare to these other strategies?
There have been numerous attempts to treat patients with other therapeutic approaches including cell-based therapies, but that hasn’t yet demonstrated any improvement. The same so far with the gene therapies for dry AMD. The previous attempts at bionic vision have all been in patients with hereditary retinal degenerations, but nothing before had been attempted in this much larger patient population with atrophic age-related macular disease.
We do have the first pharmacological drugs for geographic atrophy with successful Phase 3 clinical trials. The approach here is to repetitively inject complement inhibitors into the eye, which only slows disease progression. There has been no improvement with this type of treatment.
Q: What is the patient experience after surgery, and does it involve training?
We’ve learned there’s a rehabilitative process after the surgery where they’re continually trained to get the most of the system, which is very important. It needs discipline and for the patients to commit to the training, but once they start noticing the improvement and the restored vision, they are highly motivated.
At this stage of development, there are, of course, some limitations. Fluent reading may be challenging for patients, and it’s important to manage the patient’s expectations. Sometimes in ophthalmology, we look at people who undergo cataract surgery, where you remove an opaque lens, and instantly they see better. Here, patients have to learn how to read again, so it requires effort after the surgery, and training over weeks and months to have the best possible outcome.
Q: PRIMA is significantly different from previous retinal implants. From a technology standpoint, why is it successful??
It’s built on breakthroughs in different scientific fields, from high-resolution imaging of the retina which allows us to select suitable patients who can benefit from this system, to photovoltaic technology which means that the implant can communicate seamlessly with the glasses and the processor. Twenty years ago, it required a physical cable coming out of the eye, which was not only a huge surgical challenge, but also had post-operative complications.
Q: What comes next? Do you see applications beyond geographic atrophy?
It’s the first breakthrough, and now it’s a starting point for further improvements. We want to enable patients to see again in colour, and I think there’s lots of opportunities to make the training program easier and shorten it. Perhaps we can use AI, for example, to customize it more to the individual patient, so the training is easier.
There are also lots of other potential applications in other diseases of the retina, such as inherited retinal diseases where not only the macula is affected, but where patients can go completely blind. We now know that there are over 270 different genes contributing to various inherited retinal diseases, and the big advantage of the PRIMA system is that it’s agnostic towards the specific genetic cause. Whereas in gene therapy, the treatment is typically tailored towards one specific gene, and it only works for a small number of patients.
If you or a loved one are affected by advanced dry AMD or an inherited retinal disease, you can join our patient registry to stay informed about clinical trial opportunities.
CAUTION: Investigational device. Limited by federal law to investigational use.
