First Self-Powered Artificial Retina Could Allow Normal Visual Acuity and Restoration of Color Vision
The US Patent Office has awarded patent no. 8,433,417 to Newcyte Inc. for a carbon nanostructure artificial retinal implant. Newcyte was purchased in 2009 by Natcore Technology Inc.
“There are several other patents for artificial retinas,” says Dr. Dennis Flood, Natcore’s chief technology officer and the inventor of the device, “but all of them have limitations. Some require the patient to have sight. Some restore only limited acuity, or the ability to detect motion or to distinguish between light and dark. Some are bulky and/or require prosthesis. Ours is a self-powered implant that doesn’t require a camera, a transmitter, or any other external device. It would work as long as the patient’s nerves are alive and only the rods and cones are affected. And it has the potential to be wavelength selective, so that color vision could be reintroduced to people whose only prospect now is a cloudy black-and-white.”
The need for this artificial retina is substantial. According to the American Society of Retina Specialists (ASRS), an estimated 15 million Americans have age-related macular degeneration (AMD). ASRS also says that retinitis pigmentosa, a genetic disease, affects one in 4,000 Americans. Natcore believes that both of these disorders could be corrected with its artificial retina.
The Natcore retina comprises an array of carbon nanotubes, grown vertically on a substrate. The nanotubes are coated with a semiconducting material, in effect wrapping a solar cell around them, with the tips of the nanotubes exposed and arranged to extend into the ganglion nerves. When light enters the eye and is focused by the lens onto the artificial retina, a voltage buildup causes the nerves to fire, acting like a synapse and sending a signal to the brain. The coated carbon nanotubes act like rods or cones, the eyes’ photoreceptors that convert light into signals that can stimulate biological processes.
The Natcore device would be surgically implanted. It would be a flat round disc with a diameter of approximately 4mm, roughly the size of a pencil eraser.
Dr. Flood has 33 years’ experience in developing solar cell and array technology for both space and terrestrial applications at the NASA Glenn Research Center in Cleveland, where he served as chief of the photovoltaic and space environments branch. He was moved to invent this artificial retina when his wife lost the macula of her left eye at a relatively early age due to a form of wet macular degeneration. His invention uses some of the same carbon nanotube technology already owned by Natcore.
“Given our recent advances with black silicon, the selective emitter, and the flexible solar cell, we have an embarrassment of riches,” says Chuck Provini, Natcore’s president and CEO. “The path to commercialization for those three applications is now a relatively short one, while our artificial retina will require much more time. Because of its huge potential and the immediate need for it, we’ll probably look for a joint venture partner, a licensee, or an outright buyer to take it to market.”
Newcyte was founded by Dr. Flood and Prof. Andrew Barron, two of Natcore’s cofounders.