FDA Approves Retinal Prosthesis, a 'Bionic Eye'

Linda Roach

Disclosures

February 14, 2013

The US Food and Drug Administration (FDA) gave marketing approval Thursday to a retinal prosthesis that can enable blind people with advanced-stage retinitis pigmentosa (RP) to avoid obstacles in their path and read large letters.

The Argus II Retinal Prosthesis System (Argus II) will not restore normal vision to patients with RP, according to the device’s maker, Second Sight Medical Products Inc, Sylmar, California. Instead, it produces patterns of light that the brain learns to interpret as specific objects in the environment.

"In the patients that have been implanted to date, the improvement in the quality of life has been invaluable," device investigator Mark Humayun, MD, PhD, said in a press release from Second Sight. Dr. Humayun is the Cornelius Pings Professor of Biomedical Engineering and a professor of ophthalmology, biomedical engineering, and cell and neurobiology in the Doheny Eye Institute at the University of Southern California, Los Angeles.

"The fact that many patients can use the Argus implant in their activities of daily living such as recognizing large letters, locating the position of objects, and more, has been beyond our wildest dreams, yet the promise to the patients is real and we expect it only to improve over time," he added.

An estimated 100,000 people in the United States have RP, the umbrella term for a group of inherited degenerative diseases of the retina. By age 40, most patients with RP are legally blind, according to the Foundation Fighting Blindness. Patients with advanced RP typically can detect only extremely bright lights.

Argus II Retinal Prosthesis System

The FDA approved the Argus II for use in adults, age 25 years or older, who have bare or no light perception in both eyes, evidence that their inner retinal layer is functioning, and a history of being able to see forms. Recipients must agree to return for follow-up examinations and visual rehabilitation.

After the patient receives the implant, the Argus II works in the following way, according to Second Sight:

  • A miniature camera, located on a pair of eyeglasses, sends video over an attached cable to a small computer, which the blind person must carry.

  • The computer converts the video into instructions for the implant, then sends them back to the eyeglasses over the cable.

  • The eyeglasses unit transmits these instructions wirelessly to an antenna connected to the implant.

  • The antenna sends the signals to an electrode array resting on the retina, causing the electrodes to emit small electrical pulses.

  • The pulses activate retinal ganglion cells, which send signals to the brain.

  • The brain perceives these signals as patterns of light, which the patient "sees."

  • The patient learns to correlate certain patterns with the objects they represent.

FDA approval will allow Second Sight to expand the availability of the Argus II procedure around the United States later this year, the company said. Until then, it is encouraging patients with RP and retinal surgeons to notify the company of their interest (www.2-sight.com, 818-833-5000).

Internationally, fewer than 50 people have received an Argus II implant since it gained the European CE Mark in 2011, a Second Sight spokeswoman said. In the US trial, 20 people have received implants, and they have been followed for 5 to 8 years.

Dr. Humayan has received consulting fees, lecture fees, and grant support from Second Sight. He also owns equity in the company, plus patent/royalty interests.

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