Artificial Retina Restores Vision in Retinitis Pigmentosa

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For people who have retinitis pigmentosa, the future has generally promised blindness. Now a new artificial retina has been shown to restore some vision in a small group of people with this progressive eye disease.

Artificial retina can restore some sight

Retinitis pigmentosa (RP) is a term that refers to a group of inherited diseases that cause degeneration of the retina. Individuals who have retinitis pigmentosa gradually lose their vision because cells called photoreceptors die. Some forms of retinitis pigmentosa and related diseases include Bardet-Biedle syndrome, Leber’s congenital amaurosis, and Usher syndrome, among others.

Recently, scientists implanted an artificial retina, which had been approved by European regulators, in 30 patients with retinitis pigmentosa. A camera, mounted on dark glasses, then sends signals to electrodes implanted in the retina, and these signals are transmitted to the optic nerve. The system is called Argus II and is made by Second Sight.

In the small study of 30 patients who received the implant, the previously blind individuals were able to see motion, color, and light, distinguish the outlines of objects, and read large letters on a computer screen.

According to Lyndon Da Cruz, a consultant ophthalmic surgeon at Moorfields Eye Hospital, London, who treated seven of the patients in the study, “This demonstrates that plugging in technology to the neural structure of the eye is possible, and that this can integrate stably over a long period.”

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The procedure first involves implanting the device, which includes a radio receiver and an electrode pad that stimulates specific cells in the retina. Once the patient has recovered from the surgery, he or she can learn how to use the camera mounted on the glasses. Patients need to wear a computer, which is about the size of a wallet, around their neck.

According to a CBS News report, although the artificial retina has only been approved in Europe thus far, the Food and Drug Administration (FDA) will hopefully be next. CBS News Medical Correspondent Dr Jennifer Ashton noted on “The Early Show” that Second Sight hoped to file an application with the FDA for approval later in 2011.

Approximately 100,000 people in the United States have retinitis pigmentosa, and globally it affects about 1 in 4,000 people. Overall, about 400,000 have RP or a related retinal disorder. Although RP is typically diagnosed in adolescents and young adults, it can be identified in younger people. Most people who have retinitis pigmentosa are legally blind by age 40.

For now, the artificial retina is costly: the device is about $100,000, not including the surgery to implant it. It is not certain whether insurance will cover the cost. Second Sight has applied for approval for reimbursement in many countries, some of which have responded positively.

The new artificial retina may help patients who have retinitis pigmentosa regain some vision. Researchers continue to work on improving the technology, and they believe the device will also help individuals who have other vision problems.

SOURCES:
CBS News, March 2, 2011
Foundation Fighting Blindness
The Australian, May 30, 2011

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