A new material could enable light to stimulate blind retinas, bringing eyesight to those who are currently unable to see. Formed into a sheet, the new film could be placed over the human retinas that have degenerated or been damaged, bringing sight back to the patient.
Human retinas take photons of light, and convert the energy into electrical signals, which are then sent from the eye to the brain, where the images are processed.
Nanorods and nanotubes, constructed from semi-conductor materials, were developed into a light-sensitive film, able to convert light into electrical signals that can be transmitted without the use of wires. The material is also flexible enough to be utilized in patients, placed over their own inactive retinas.
"This is a pioneering work demonstrating the use of highly tailored semiconductor nanocrystals in activation of biomedical functionalities. We hope this can lead to future implementation of this approach in retinal implants," Uri Banin of the Hebrew University said.
Developing chicks with inactive retinas were implanted with tiny pieces of the new film, and light sensitivity in their retinas was seen to increase. This provides direct, if preliminary, evidence that the revolutionary film could be used to develop replacements for natural retinas.
Carbon nanotubes were utilized in the film, along with a polymer, to network the nanorods to the human optical system. Electrical signals successfully flowed through the system, providing the ability of delivering a strong signal for processing by the brain.
Age-related macular degeneration (AMD) is the leading cause of central vision around the globe. The common condition affects the macula, a small region near the center of the retina. This area is responsible for gathering light from objects straight ahead of the viewer. Although the condition does not cause total blindness, the symptoms often get worse over time. Sufferers of AMD could be among those who could experience the greatest benefit from the new material.
Researchers believe their new film delivers a higher resolution than is possible with earlier technology, and is better-able to deliver signals to retinas incapable of natural processing. A significant amount of researcher remains before the new material can be used to create full-operational artificial retinas. However, this new development could prove a "raw material" that could be used to bring eyesight back for many blind people.
Nano-technology is used to create the new material, which could replace current technology, which relies on conventional electronics to convert light to nerve signals.
Development of the new film that could, one day, be used to create artificial retinas was detailed in the journal Nano Letters.
