February 20, 2008 It has to be among the most powerful examples of the miraculous potential of modern science and technology - restoring sight to the blind. Following approval from the US FDA last year, Second Sight Medical Products Inc has now announced that enrollment is complete for the first phase of clinical trials on a system that restores a basic level of sight to sufferers of retinal eye diseases. Enrollment at key European sites also underway. Ten subjects have been recruited for the Phase I trial of the second-generation electronic retinal implant known as The Argus II, which is capable of restoring rudimentary vision using an external camera and transmitter mounted in eyeglasses linked to a tiny array of 60 electrodes that are attached to the retina.
The image captured by the camera on the glasses is sent to a video processor which converts the image to an electronic signal and sends it to the transmitter on the sunglasses. This information is then sent wirelessly to the implanted receiver which sends the signals through a tiny cable to the electrode array, stimulating it to emit electrical pulses and induce responses in the retina that travel through the optic nerve to the brain.
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The system is designed to treat blindness caused by Retinitis Pigmentosa (RP), a group of inherited eye diseases that affect the retina. RP causes the degeneration of photoreceptor cells in the retina, which capture and process light helping individuals to see. As these cells degenerate, patients experience progressive vision loss.
We are pleased that Second Sight, along with our fantastic clinical partners, was able to fully enroll the US trial in a timely manner, said Robert Greenberg, MD, PhD, President and CEO of Second Sight, and a leader in the field of retinal prostheses for more than 15 years. Although it is too early to comment on the clinical data, each device continues to function as expected, and all participants are using their systems at home daily.
The project is supported by the National Eye Institute (NEI) of the National Institutes of Health (NIH), and the Department of Energy's Office of Science (DOE) Artificial Retina Project, which is helping to advance the implant's design and construction and pursue the development of smaller, higher resolution devices.
The Phase I trial is taking place at four leading ophthalmic centers throughout the US, including Doheny Eye Institute at the University of Southern California (USC), Wilmer Eye Institute at Johns Hopkins University (Baltimore), the University of California at San Francisco, and the Retina Foundation of the Southwest (Dallas).
Second Sight aims to expand the three-year Investigational Device Exemption (IDE) trial - the only long-term study of a retinal prosthesis currently being conducted - to include other trial sites located in New York (Columbia University Medical Center and Lighthouse International), Philadelphia (Scheie Eye Institute and Wills Eye Hospital) and Atlanta (Emory University and Atlanta V.A. Rehab R&D Center).
Internationally, the Argus II study began in Mexico in the fall of 2006 at Centro de Retina Medica y Quirurgica, SC, Centro Medico Puerta de Hierro, CUCS, Universidad de Guadalajara (Guadalajara, Jal.). More recently, enrollment has just begun at two European sites, including Service d'Ophtalmologie, HÃ´pital Cantonal, Universitaire de GenÃ¨ve (Geneva, Switzerland) and Le Centre Hospitalier National D'Ophtalmologie Des Quinze-Vingts (Paris, France). A third study site at Moorfields Eye Hospital in London has recently received government approval and is expected to begin enrollment shortly.
Mark Humayun, MD, PhD, Professor of Ophthalmology, Biomedical Engineering, and Cellular and Neurobiology at the Doheny Eye Institute implanted six subjects with the first generation 16-electrode (Argus™ 16) between 2002 and 2004. The study demonstrated the ability of participants to detect when lights are on or off, describe an object's motion, count discrete items, as well as locate and differentiate basic objects in an environment.
"The pioneering efforts of the individuals that participate in this clinical trial will lead to advances for the many people in the world afflicted with blindness," said Dr. Humayun.
"We are excited about the progress being made in the development of this artificial retina technology," says Stephen Rose, PhD, Chief Research Officer, Foundation Fighting Blindness (FFB). "FFB supported early preclinical studies of this technology, because of its great potential for giving vision to people with the most advanced retinal disease and we are pleased to have helped advance the prosthesis into critical clinical trials."
More information about the trials can be found at Second Sight.View gallery - 4 images