Article Date: 6/1/2013

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Argus II Improves Sight in RP

BY STUART MICHAELSON, CONTRIBUTING EDITOR

According to Greek mythology, Argus Panoptes was a 100-eyed giant, thought to be all-seeing.

And according to those close to the source, including the FDA and the director of Retina Research at Wills Eye Institute, Philadelphia, PA, a new implantable device bearing that mythological name may well become a giant in battling the devastating effects of a rare inherited sight disorder.

Wills Eye was among the first medical facilities involved in clinical trials for the device, Argus II Retinal Prosthesis, made by Second Sight Medical Products, Inc., of Los Angeles, CA, and approved for use in Europe in 2011. It received FDA approval in February for use on patients age 25 and older who have advanced retinitis pigmentosa. More than 100,000 people in the United States suffer from the condition.

Patients must have little or no light perception in both eyes but still have signs of at least some retinal function to be eligible for the surgery. About 10,000 patients are thought to be at stages advanced enough that they might benefit from Argus II, sometimes called a “bionic eye.”

HOW ARGUS II WORKS

The device includes a small video camera and transmitter mounted on a pair of eyeglasses. The camera’s images are processed into electronic data, which are wirelessly transmitted to electrodes implanted into the retina of the patient.

Research and development supported by $100 million from the National Institutes of Health, the National Science Foundation, and the Department of Energy got the process moving.

Philadelphia is among five cities (the others being Baltimore, Dallas, Los Angeles, and San Francisco) with enrollment centers for Argus II.

EARLY RESULTS SEEN

Allen C. Ho, MD, Wills Eye Institute’s Retina Research director, implanted Argus II (Argus I was tested from 2002 to 2004) into the retinas of two middle-aged patients, both of whom lived with their families, five years ago as part of clinical trials for the device, which is not yet commercially available.

Dr. Ho’s male patient, whose preoperative level of independence was more advanced than that of Dr. Ho’s female patient, had trouble with the device. The woman, though, uses it routinely and has been a success story thus far. She can sort colors — such as distinguishing light clothing from dark — and can navigate to some extent on her own, able to avoid obstacles and distinguish doors and windows.

“This is a very exciting technology for patients who otherwise have no treatment,” Dr. Ho says. “There are hurdles to overcome, but we think we are clearly moving in the right direction” in terms of allowing patients who are essentially sightless to gain a measure of independence and connection with their surroundings.

Those hurdles are both financial and medical: The cost of the procedure, about $100,000, may eventually be covered by insurance, Dr. Ho says, adding that Second Sight is working with Medicare to get the procedure covered. Dr. Ho adds there is also the risk with such a procedure of complications, such as infection, retinal detachment, and complete vision loss.

images

The Argus II implant and glasses.

While Argus II “is not a miracle,” Dr. Ho notes, and it will not fully restore vision, it “certainly can allow people to improve their independence and give them the ability to detect doors and edges and shapes and navigate their environment better. The technology is simply amazing and will only improve with time.” RP



Retinal Physician, Volume: 10 , Issue: June 2013, page(s): 65