The Science Driving Vision Restoration After Retinal Degeneration
Blindness is not a single entity but a spectrum of visual impairment determined by where the visual pathway fails. While optical deficits can be corrected with tools as simple as glasses, neurodegenerative retinal diseases pose a far greater challenge. Vision restoration efforts now span electronic retinal implants, optogenetic reprogramming of surviving neurons, and regenerative strategies to replace lost photoreceptors. Built on decades of basic science and interdisciplinary collaboration, these emerging therapies are moving into clinical trials with the goal of restoring not just light perception, but meaningful, high-quality vision that improves daily life.
"Vision is complicated, and we don’t yet have a complete understanding of how it works, let alone how to prevent these complex diseases," says Juliette McGregor , an assistant professor of ophthalmology at the University of Rochester Medical Center. "Vision is a really fundamental sense that helps us with the activities of daily life, but it also brings us a lot of joy. Sharing a smile or seeing a beautiful sunset are important not just for independence, but also for our well-being. Researchers are working hard to create new technologies and treatments designed to allow people with vision loss to regain some visual performance."
Transcript
00:00:00 I think blindness is can be really emotive and loaded term. might imagine that everything's totally black, but of course, there's a spectrum of visual impairment the type of vision loss that you have is obviously linked to the to the part of the visual pathway that is affected Have you ever wondered if it might be possible one day to restore vision? So the structures of the eye particularly the cornea and the lens, which are the transparent parts of the front of the eye, are really working like a camera lens. So they're collecting the light and they're focusing it to a particular position in the human eye.
00:00:32 Actually, sensor that detects the light is actually quite smart. It's a bunch of neurons that are connected to the brain. Some of them are light sensitive, and they do the processing to create a visual perception. And I can show you what this looks like. This is an image of the human eye taking a microscopic scale, The individual rods and cones, these are cell types that often degenerate in, retinal diseases where people become blind. And these diseases, when neurons are dying, that's really where it's challenging
00:00:59 to restore someone's vision, because it's not possible just to to take them out and put them back in. That's what we're trying. But it's it's a really difficult problem. So I think that's really where the emphasis on trying to delay the onset of some of these, degenerative conditions is really important. And that's why there's been a huge amount of research over decades, really supported by the or the scientific community, and the patients who volunteer their time to try to find strategies to preserve vision for as long as possible.
00:01:26 But once it's gone, what can we do? And I think that's where these vision restoration technologies that are currently under development really come in. visual problems can occur at any stage of the pathway from these optical elements at the front, to the neurons at the back or even in the brain itself. one of the most common forms of, visual impairment is, if your vision looks a bit blurry because your lens is not focusing, the light to create quite the correct plane. in that case, we would use perhaps the oldest form of vision restoration technology
00:01:57 that we've been using for hundreds of years. We would use eyeglasses. And that's been working very successfully. But not all vision problems are as easily solved as that. some diseases lead to the death of neurons in the eye? That's not easy to repair. research community is really working furiously to try to develop some of these, new vision restoration therapies and several of them are now in clinical trials, and we're trying to evaluate whether they're actually, successful, what kind of vision they're actually able to restore.
00:02:29 So one of those approaches is using a little, photosensitive chip. So light falls on the chip and it produces electrical stimulation. And you can surgically implant that under the retina to try to stimulate the remaining neurons and bring back some light perception. Another strategy is to try to make other cell types that still remain in the eye, but are not light sensitive into kind of artificial photoreceptors that will detect light. And what a way to do that is to take light sensitive proteins that are originally found in algae and express them instead in the eye. that's, a technique called optogenetics,
00:03:06 which has been developed over many years by researchers really focused in a different area, not necessarily thinking about vision restoration. But this is the way that science works. We can, really understand the basic science and then find an interesting application and then work together to make that happen. lastly, there's a possibility of actually trying to replace the missing cells directly. So instead of using a chip or making other cell types light sensitive, maybe we could actually grow new photoreceptors in the lab
00:03:38 and insert those into the eye and get those to connect back up with the remaining retinal neurons. And so that's a technology called, regenerative medicine, that's currently under development. we're not forcing another cell type to respond. We're not trying to kind of artificially make these cells. These are actual food receptors. So they should be able to take advantage of the, of the natural processing and the kind of signal processing that takes place in, in the brain to restore higher quality of visual perception.
00:04:10 the current therapies that are in clinical trials are already showing some promising results. as we think about future therapies, obviously the most important thing to start with is that we giving something to patients, which improves their their daily life and their activities of daily living. And I think we're already starting to get to the point where that might be achievable. But down the road, really, we'd like to restore high quality vision so that you are able to see your friends smile and you are able to appreciate a sunset, those kinds of things which are currently,
00:04:39 kind of off the charts, difficult to achieve. so researchers from lots of different fields need to come together to solve these really intractable problems. And the project that I am working on at the moment is called, an "Audacious Goals Project," because really trying to restore vision after it's been lost is a really audacious and difficult challenge. So the interdisciplinary nature of vision research is integral to our ability to figure out new treatments. And one of the strengths of the University of Rochester is that we have a center for visual science, which has folks from the Institute of Optics, as well
00:05:12 as, the Flaum Eye Institute and Neuroscience, everyone working together. So to get to the point where therapy is actually entering clinical trials, we've really been building on decades and decades of scientific research, many generations of students and patients that are involved in these studies. For example, how do you grow a photoreceptor, in a lab in a dish. Right. That's kind of a strange thing to be able to do. it's because researchers figured out that you can take, cell type, for example, skin cells, and you can treat them with factors that cause those cells to forget that the skin cells and treat them
00:05:52 with different factors to drive them towards a photoreceptor fate. And that's not something that you just figure out overnight. It takes many decades of research from folks in cell biology, folks with understanding of, chemistry and development So we're really building on decades and decades of work and hundreds of years of work to get to these kind of positions where we are able to now start to offer treatments, for debilitating human diseases.