The technology could help millions of people worldwide suffering from neurodegenerative diseases that affect eyesight, including macular degeneration, retinitis pigmentosa and loss of vision due to diabetes.
Despite advances in the development of retinal prostheses over the past two decades, the engineers say that the performance of devices currently on the market to help the blind regain functional vision is still severely limited.
Gabriel Silva, professor in bioengineering and ophthalmology at UC San Diego and founder of Nanovision, said: "We want to create a new class of devices with drastically improved capabilities to help people with impaired vision."
This prosthesis consists of arrays of silicon nanowires that simultaneously sense light and electrically stimulate the retina accordingly. The nanowires are claimed to give the prosthesis higher resolution than anything achieved by other devices. It also includes a wireless device that can transmit power and data to the nanowires.
One of the main differences between the researchers' prototype and existing retinal prostheses is that their system does not require a vision sensor outside of the eye to capture a visual scene and transform it into alternating signals to sequentially stimulate retinal neurons. Instead, the silicon nanowires mimic the retina's light-sensing cones and rods to directly stimulate retinal cells. Nanowires are bundled into a grid of electrodes, directly activated by light and powered by a single wireless electrical signal. The engineers say this direct and local translation of incident light into electrical stimulation makes for a much simpler - and scalable - architecture for the prosthesis.
Nanovision plan to develop the technology further and translate it into clinical use, with the goal of restoring functional vision in patients with severe retinal degeneration. Animal tests with the device are in progress, with clinical trials following.
