On February 14, 2013, the FDA approved an “artificial retina” device that will be the first treatment to give limited vision to people who are blind. The artificial retina is a sheet of electrodes surgically implanted in the eye, whereby the patient who is outfitted with a pair of glasses with an attached camera and a portable video processor can actually identify outlines or forms. The combination of the electrodes and equipment allow signals to bypass the patient’s damaged retina and transmit signals to the brain. While the device will not restore vision to patients, it may allow them to detect light and dark in the environment, aiding them in identifying the location or movement of objects or people.
The device alone will cost about $150,000. Additional costs will include the surgery and training to use it.
The device, known as the Argus II Retinal Prosthesis System (Argus II), manufactured by Second Sights Medical Products, Inc., is meant to be used by adults, age 25 years or older, with severe to profound advanced retinitis pigmentosa (RP). These patients have no light perception in either eye or “bare light perception,” the ability to perceive light, but not the direction from which it is coming. The primary group of patients have evidence of intact inner layer retina function and a previous history of the ability to see forms. Patients must also be willing and able to receive the recommended post-implant clinical follow-up, device fitting, and visual rehabilitation.
It is noteworthy that the FDA approved the Argus II as a humanitarian use device, an approval pathway limited to those devices that treat or diagnose fewer than 4,000 people in the United States each year. To obtain approval under this pathway, a company must demonstrate a reasonable assurance that the device is safe and that its probable benefit outweighs the risk of illness or injury. The company also must show that there is no comparable device available to treat or diagnose the disease or condition.
In Europe, the device received approval in 2011 to treat a broader group of people, including those with severe blindness caused by any type of outer retinal degeneration, not limited to RP. However, the device is only marketed in Europe as a treatment for RP. In the U.S., additional clinical trials will need to be completed before the company can seek broader FDA approval.
The FDA reviewed data that included a clinical study of 30 study participants with RP who received the Argus II; patients were monitored for adverse events related to the device or to the implant surgery and regularly assessed their vision for at least two years after receiving the implant. Results from the clinical study show that most participants were able to perform basic activities better with the device than without it. Some of the activities tested included locating and touching a square on a white field; detecting the direction of a motion; and recognizing large letters, words, or sentences.
While 19 of the 30 study participants did not experience adverse events, the remaining 11 experienced adverse events including erosion of the conjunctiva (the clear covering of the eyeball), dehiscence (splitting open of a wound along the surgical suture), retinal detachment, inflammation, and hypotony (low intraocular pressure). However, only two of the study participants had to have the device removed.