Could the complex function of rods and cones — converting light into signals that the brain can interpret as vision — be replicated in a pair of high-tech glasses? Based on the recent research advances made by Dr. Sheila Nirenberg at Weill Cornell Medical College, it looks like a possibility.
What that might mean someday is that these glasses could provide relatively natural vision for someone who has completely lost his or her eyesight to a retinal degenerative disease, such as retinitis pigmentosa or macular degeneration.
Keep in mind that this vision-restoring approach — which would need to work in combination with a gene therapy or retinal prosthetic device — is still several years away from moving into a human study.
What Dr. Nirenberg has demonstrated thus far in mice is that her retinal processing technology was able to reproduce, to an impressively accurate extent, the intricate “code” that rods and cones produce and send back to the brain. Tests showed that the mice were able to process the code and see. Her next step is to evaluate the technology in a larger animal.
Dr. Nirenberg described her work-in-progress during a Technology, Education, Design, or TED, conference last year:
Her high-tech glasses will work in tandem with optogenetic gene therapy. The idea is that the code from the glasses — sent in the form of light — will be captured by ganglion cells in the retina made light-sensitive by an optogenetic treatment. The ganglion cells, which often survive after rods and cones are lost to disease, will then take the information and direct it through the optic nerve to the brain.
When I was in Israel last spring, I met another brilliant scientist, Dr. Shy Shoham of Technion University, who is developing similar technology. He’s even investigating acoustics — using sound waves — for delivering complex visual information to the degenerated retina.
What’s significant about these approaches is they are targeted at providing a much more natural and complex visual experience than current artificial retinas on the market or in clinical trials or optogenetic therapy alone.
We don’t necessarily think about the complexity of vision as we go about our activities of daily living — for example, while walking, driving or talking to a friend. But our retinas have to be very sophisticated to interpret brightness, contrast, color, motion, depth and other subtle aspects of the visual world around us.
“Seeing” is an incredibly complex activity. So the more accurately scientists like Drs. Nirenberg and Shoham can replicate these complexities, the better we’ll be able to restore vision that’s truly natural.