One biotech startup wants to restore vision in blind patients with a gene therapy that gives light sensitivity to neurons that don’t normally possess it.
The attempt, by Ann Arbor, Michigan-based Retrosense Therapeutics, will use so-called optogenetics. Scientists have used the technique over the last few years as a research tool to study brain circuits and the neural control of behavior by directing neuron activity with flashes of light. But Retrosense and others groups are pushing to bring the technique to patients in clinical trials.
The idea behind Retrosense’s experimental therapy is to use optogenetics to treat patients who have lost their vision due to retinal degenerative diseases such as retinitis pigmentosa. Patients with retinitis pigmentosa experience progressive and irreversible vision loss because the rods and cones of their eyes die due to an inherited condition. If the company is successful, the treatment could also help patients with the most common form of macular degeneration, which affects nearly a million people in the United States. The U.S. Food and Drug Administration hasn’t approved any therapies for either condition.
Retrosense is developing a treatment in which other cells in the retina could take the place of the rods and cones, cells which convert light into electrical signals. The company is targeting a group of neurons in the eye called ganglion cells. Normally, ganglion cells don’t respond to light. Instead, they act as a conduit for electrical information sent from the retina’s rods and cones. The ganglion cells then transmit visual information directly to the brain.
Doctors would inject a non-disease causing virus into a patient’s eye. The virus would carry the genetic information needed to produce the light-sensitive channel proteins in the ganglion cells. Normally, rods, cones, and other cells translate light information into a code of neuron-firing patterns that is then transmitted via the ganglion cells into the brain. Since Retrosense’s therapy would bypass that information processing, it may require the brain to learn how to interpret the signals.
So far, Retrosense and its academic collaborators have shown that the treatment can restore some vision-evoked behaviors in rodents. The treatment also seems safe in nonhuman primates. The optogenetically modified ganglion cells of these primates are light-responsive, but behavioral tests aren’t possible, as there are no nonhuman primate models of retinal degeneration, says Retrosense CEO Sean Ainsworth.
Retrosense plans to begin its first clinical trial in 2013 with nine blind retinitis pigmentosa patients.
This new data poisoning tool lets artists fight back against generative AI
The tool, called Nightshade, messes up training data in ways that could cause serious damage to image-generating AI models.
The Biggest Questions: What is death?
New neuroscience is challenging our understanding of the dying process—bringing opportunities for the living.
Rogue superintelligence and merging with machines: Inside the mind of OpenAI’s chief scientist
An exclusive conversation with Ilya Sutskever on his fears for the future of AI and why they’ve made him change the focus of his life’s work.
How to fix the internet
If we want online discourse to improve, we need to move beyond the big platforms.
Get the latest updates from
MIT Technology Review
Discover special offers, top stories, upcoming events, and more.