Updates on the Progress of Clinical Trials for a Retinal Implant for Retinitis Pigmentosa

How It Began

On November 3, 2010, a report entitled Subretinal electronic chips allow blind patients to read letters and combine them to words was published online in the Proceedings of the Royal Society B: Biological Sciences. Proceedings B is the Royal Society’s biological research journal, dedicated to the rapid publication of high-quality research papers.

The paper summarized a 15-year research project to develop and test a functional retinal implant for patients with retinitis pigmentosa (RP). The project was headed by Eberhart Zrenner, M.D., founding director of the Institute for Ophthalmic Research in Tübingen, Germany. The retinal implant was developed with funding from the German government and Retinal Implant AG.

How the Retinal Implant Device Works

The cable from the implanted chip in the eye leads under the temporal muscle to exit behind the ear and connects with a wirelessly operated power control unit. The wireless control unit is attached to a neckband that allows the unit to rest on the chest.

The Initial Research

WebMD also provided an explanation of the device and the initial participants:

The implants are controlled by a small handheld external unit, which receives signals from a coin-sized device implanted under the skin directly behind the ear. This device is connected to the chip in the retina.

A total of 11 patients received the chip device [Note: Each required a six-hour implantation surgery] in the pilot study starting in 2005, but the researchers changed the placement of the chip in the retina in an effort to improve outcomes after the first eight patients were treated. [Note: The device did not work for these initial eight patients because it was not implanted deeply enough within the eye.]

The last three patients treated were able to locate bright objects on a dark table after receiving the implant, and two of the three could name some specific objects the first time they saw them.

The Initial Clinical Trial

Retina Implant AG’s initial human clinical trial was conducted with nine subjects, from May 19, 2010 to July 28, 2011 in Tübingen, Germany. The results indicated that patients achieved their best visual acuities to date, with the majority of patients experiencing restoration of useful vision in daily life.

In addition, patients reported the ability “…to see objects 30 feet away and to read numbers on a pair of dice.” The subretinal surgical technique to implant the device continued to be safe and effective, and adverse events were “minimal and correctable.”

A United States Collaboration Announced

In March 2011, Retina Implant AG announced a partnership with Wills Eye Hospital and Institute in Philadelphia as the lead U.S. clinical trial investigator site. The Wills partnership marked the expansion of Retina Implant AG’s technology to North American studies.

A Second Clinical Trial

On December 7, 2011, Retina Implant AG announced the initiation of the multi-center phase of the company’s second human clinical trial, which will expand to five new European sites: Oxford, London, Budapest, and two additional locations in Germany. Unlike the first human clinical trial, the retinal implant will be permanent and patients will use the implant in real-life settings.

VisionAware will continue to provide updates of this highly anticipated research as they become available.

Sources: BusinessWire; Optician; Ophthalmology Times Europe