Safety concerns may stymie FDA approval for 1st-of-its-kind retinal prosthesis

September 27, 2012 by MassDevice staff

The FDA's Ophthalmic Devices Panel will convene tomorrow to review Second Sight's Argus II retinal prosthesis for the blind, but a high rate of revision surgeries and the device's potential for long-term safety risks may prevent the novel device from reaching the market.

Second Sight's Argus II retinal prosthesis

The FDA's Ophthalmic Devices Panel will convene tomorrow to discuss potential approval for Second Sight Medical Products' Argus II retinal prosthesis for the blind.

The "bionic eye," which uses a head-worn camera to capture a scene and process it into electrical signals that are then sent to the cells in the eye, may pose long-term risk that increase over time, according to panel documents released ahead of the meeting.

Sign up to get our free newsletters delivered right to your inbox.

In a small study conducted in support of the FDA application, 30% of Argus II recipients required multiple revision surgeries to manage adverse events more than 2.5 years after the procedure. More than 40% experienced non-serious "fibrotic events," which include retinal detachment and retinal tears, and 10% suffered serious fibrotic events.

"While there are concerns regarding the safety profile based on premarket data, there is also concern about the possibility that the frequency of adverse events could increase over time and/or the events could worsen in severity," according to panel documents

Second Sight is seeking humanitarian device exemption for the Argus II system in patients aged 25 and older who have severe to profound retinitis pigmentosa, experience bare or no light perception in both eyes and have "previous history of useful form vision."

The FDA's HDE approval system is designed to incentivize development in devices that treat conditions affecting 4,000 or fewer people in the U.S. each year. The application system is similar to the pre-market approval process with the exception that the device maker isn't held to the same efficacy standards as long as the device can demonstrate safety.

The implant, which may be surgically place in one or both eyes, includes an antenna, an electronics case and an electrode array, according to the company's website. The external equipment includes glasses, a video processing unit and a cable.

Should Argus II win FDA approval, it will be the 1st retinal prosthesis on the U.S. market, according to panel documents.

The panel will also consider whether clinical studies for the Argus II are enough to demonstrate safety and efficacy. Second Sight conducted a study involving 30 patients who were implanted with 2 different device configurations, neither of which match the version of the device being considered for market approval.

In addition, the study was non-randomized, researchers were un-blinded and "numerous modifications" were made during the course of the trial, according to a note to panelists.

The Argus II won CE Mark approval in the European Union last year. The device is also in the midst of a 3-year U.S. clinical trial, expected to enroll 30 patients and close in July 2014, according to regulatory filings.

Comments