Study Findings:

• Scientists have developed a new eye implant, using arrays of silicon nanowires that sense light and electrically stimulate the retina, which may help restore vision in millions of people worldwide.
• The advance brings us a step closer to restoring the ability of neurons in the retina to respond to light.
• The researchers from University of California San Diego and US-based startup Nanovision Biosciences showed response to light in a rat retina interfacing with a prototype of the device in vitro.

Importance of the Findings:

• The technology could help tens of millions of people worldwide suffering from neurodegenerative diseases that affect eyesight, including loss of vision due to diabetes.
• Performance of current retinal prostheses to help the blind regain functional vision is still limited.
• “We want to create a new class of devices with drastically improved capabilities to help people with impaired vision.

Groundbreaking technologies

The new prosthesis relies on two groundbreaking technologies.

• One consists of arrays of silicon nanowires that simultaneously sense light and electrically stimulate the retina accordingly.
• The nanowires give the prosthesis higher resolution than anything achieved by other devices – closer to the dense spacing of photoreceptors in the human retina.
• The other breakthrough is a wireless device that can transmit power and data to the nanowires over the same wireless link at record speed and energy efficiency.
• The new system does not require a vision sensor outside of the eye to capture a visual scene and then transform it into alternating signals to sequentially stimulate retinal neurons.
• Instead, silicon nanowires mimic the light-sensing cones and rods to directly stimulate retinal cells.
• Nanowires are bundled into a grid of electrodes, activated by light and powered by a single wireless electrical signal.

Simple architecture

• This direct and local translation of incident light into electrical stimulation makes for a much simpler and scalable architecture for the prosthesis.
• “To restore functional vision, it is critical that the neural interface matches the resolution and sensitivity of the human retina.
• Power is delivered wirelessly, from outside the body to the implant, through an inductive powering telemetry system.

Source: The Hindu