Scientists are still a long way from creating a visual prosthesis that works as well as a real human eye. But, engineers are making steady progress in what was once the realm of science fiction.
One of their promising new devices, a bionic vision system based on photovoltaic implants, is awaiting approval for human clinical trials in Europe. A second system, based on in vitro studies of the retina, could be ready for animal testing within four or five years. Both inventions have the same goal: to give back some measure of sight to people with progressive diseases of the retinaespecially retinitis pigmentosa and macular degeneration.
The new device doesnt require the implantation of a bulky electronics case and antenna, or a cable coming out of the eye.
According to the National Institutes of Health, retinitis pigmentosa is the leading cause of inherited blindness, affecting 1 in about 4,000 people in the United States. The disease usually begins with a loss of night vision in childhood, and progresses to involve peripheral and then central vision, gradually robbing young people of the ability to read, drive, recognize faces, and do routine daily tasks.
Macular degeneration, in contrast, is one of the leading causes of vision loss in Americans 60 and older. By 2020, the NIH estimates that as many as 3 million people in the United States may be living with various stages of the disease, which gradually destroys the densely packed light-sensitive cells, called photoreceptors, in the retinas center, or macula.
Many of these folks are going to be losing their central vision, says Chip Goehring, president of the American Macular Degeneration Foundation, so it is absolutely vital that we have options for the restoration of sight, including biological and mechanical approachesstem cell therapies for photoreceptor replacement, gene therapies to restore dysfunctional retinal tissues, and prosthetic retinas that can serve an even wider population of people with vision loss.
Normal retinal tissue consists of photoreceptors: light-sensitive cells resembling rods and cones at the base of the eye, topped by interconnected layers of neurons. The signal travels from the rods and cones, through bipolar cells to ganglion cells, then via the optic nerve to several brain areas, including the visual cortex. Scientists still arent exactly sure why the rods and cones break down in patients with retinal diseases, nor have they figured out ways to prevent, slow, or reverse the process.
There is one silver lining: Retinitis pigmentosa and macular degeneration tend to spare some of the bipolar and ganglion cells. This means that the neurons in these patients retinas can be stimulated artificially, with micro-electrodes, bypassing the damaged rods and cones altogether.
Daniel Palanker, a professor of ophthalmology at Stanford University, has developed and patented numerous devices over the years to diagnose and treat eye diseases. Among them are a neurostimulator for enhancement of tear secretion in patients with dry eye syndrome, a femtosecond laser for cataract surgery, and a patterned laser scanning photocoagulator that surgeons use to treat multiple retinal disorders, including diabetic retinopathy, without excessive damage to the delicate tissues around the treatment spots.
Palankers new prosthetic device, called PRIMA, features a tiny video camera mounted atop futuristic-looking augmented reality goggles, connected to a video processor about the size of a cell phone. It doesnt require the implantation of a bulky electronics case and antenna, or a cable coming out of the eye, like a German system that has been used successfully by a handful of patients in Europe.
Instead it relies on multiple arrays of photodiodes, each about a millimeter in diameter and containing hundreds of pixels, which work like the solar panels on a rooftop. Surgeons can lay down these tiny chips, like tiles, replacing the missing light-sensitive rods and cones in the central retina.
When PRIMAs camera captures an image of, say, a flower, the video processor transmits that picture to a microdisplay mounted inside the goggles. Powerful pulses of near-infrared light illuminate this display and are projected from the goggles into the eye, like the invisible rays of a TV remote control.
The implanted photodiodes pick up these signals and convert them into tiny pulses of electrical current, which stimulate the bipolar cells directly above them. The signals propagate to the ganglion cells and then to the brain, which perceives them as patterns of light: a flower!
To test the system, researchers implanted PRIMA chips in laboratory rodents and exposed them to flashes of light, or to flickering patterns on a computer screen. By recording the resulting electrical activity in the animals visual cortices, the scientists measured their visual acuity.
It turned out that the prosthetic acuity exactly matched the 70-micron resolution of the implant, which is half the acuity of the rats natural vision, Palanker says. Since the stimulation thresholds were much lower than the safety limits, we decided to develop even smaller pixels to enable better vision. More recent behavioral tests, conducted by the French collaborators in primates, have confirmed our results with rodents.
Of course, until the implants are done in human patients, we wont know for sure.
But when human clinical trials do start later this year in Europe, they hope to achieve resolution corresponding to 20/250 vision with 70-micron pixels. That still is worse than the standard for legal blindness, 20/200, but it may be enough for a user to read very large print, or to see the face of a newborn grandchild.
In the next generation of the device, Palanker says, We should be able to put more than 12,000 pixels within 15 degrees of the visual field, taking the system to 20/150 or even better.
And while PRIMA cant reproduce color vision yetonly various shades of grayWe are working on single-cell selectivity in retinal stimulation, which might enable color perception, he says. With more experience, surgeons also might be able to expand the visual field to about 20 degrees.
Scientists ultimate dream is to build a visual prosthesis so small and powerful that it can stimulate specific neurons inside the retina, rather than sundry patches of them. Thats the goal of E.J. Chichilnisky, a Stanford professor of neurosurgery and of ophthalmology.
Think of the retina as an orchestra, Chichilnisky says. When you try to make music, you need the violins to play one score, the oboes to play a different score, and so on. Likewise, the retinas 1 million or so ganglion cells are composed of about 20 distinct types. Each plays a slightly different role in transmitting the perception of shape, color, depth, motion, and other visual features to the brain.
Since the mid-1990s, Chichilnisky has worked with a variety of physicists and engineers to develop small but powerful electrode arrays capable of measuring neural activity at the cellular level.
To better understand the patterns of electrical activity in the retina, Chichilnisky and colleagues use eye tissue taken from primates that have been euthanized for other medical studies. By placing small pieces of retinal tissue atop the microchip arrays, then exposing those samples to various patterns of light, theyve been able to record and study the distinctive electrical responses of five different types of retinal ganglion cells, which together account for 75 percent of the visual signal sent to the brain.
Theyve also developed techniques to replicate those electrical patterns, artificially stimulating the ganglion cells with high precision, comparable to the natural signals elicited by the rods and cones.
By learning how to replicate these complex signals, researchers are one step closer to their ultimate goal: a high-acuity visual prosthesis that behaves like an orchestra conductor, signaling the retinas myriad neurons to fire in precisely the right ways, at precisely the right times. Im not saying weve got it nailed, he says, but we certainly now have proof of concept for how to make a better device in the future.
The next challenge will be to fit the computing power onto an implantable electrode array that can do its job safely inside the eye, without overheating surrounding tissues, and autonomously, without any graduate students or postdocs running it, he says, laughing. If all goes well, a prototype of the implant could be ready for testing in lab animals in four to five years.
Chichilnisky and Palanker have the sense that they are pushing scientific boundariesand that their work someday may help more than blind people. Electro-neural interfaces already are being used to assist in the control of several vital organs, including the heart, bladder, and limbs. Before long, they even may be hooked up to different parts of the brain, helping people with memory loss, for example or, incredible as it sounds, even enabling telepathic communication.
We live in an era when we are starting to overcome the limitations imposed on us by our biological nature, Palanker says. This is how evolution goes.
Source:Theresa Johnston for Stanford University
Continued here:
Scientists aim to ease blindness with video goggles - Futurity: Research News
- Types of Blindness, Causes, and Their Treatment - Healthline - March 28th, 2025
- Types of blindness: Partial, total, congenital, and more - March 28th, 2025
- International collaborations helping understand the physical activity levels and well-being of children with visual impairment - Murdoch University - March 28th, 2025
- Revel in the Rainbow: Color-Blindness-Correcting Glasses Debut at Wooden Shoe Festival - Portland Monthly - March 28th, 2025
- Prevent Blindness Declares April as Women's Eye Health and Safety Month, Providing Free Educational Resources to the Public and Professionals - PR Web - March 28th, 2025
- Partial blindness hasn't stopped Oklahoma State's Stailee Heard from leading the Cowgirls into NCAAs - The Washington Post - March 28th, 2025
- Nine out of ten cases of blindness caused by glaucoma could be prevented through annual check-ups - Euro Weekly News - March 28th, 2025
- The silent sight thief: The devastating effects of glaucoma on mental health and quality of life - News24 - March 28th, 2025
- Rosie O'Donnell Celebrates Her 63rd Birthday After Move to Ireland as She Slams 'Willful Blindness' in Trump Administration - AOL - March 28th, 2025
- Partial blindness hasn't stopped Oklahoma State's Stailee Heard from leading the Cowgirls into NCAAs - Eagle-Tribune - March 28th, 2025
- The Longevity Wake-Up Call And The Blindness Of Leadership To It - Forbes - February 24th, 2025
- Album Review: Blindness // The Murder Capital - The Indiependent - February 24th, 2025
- The Murder Capital - Blindness - Northern Transmissions - February 24th, 2025
- The Murder Capital: Blindness review - independent pop | Indie - The Line of Best Fit - February 24th, 2025
- Prevent Blindness Kicks Off Second Annual "Retinopathy of Prematurity (ROP) Awareness Week," Feb. 24- March 2, 2025, as Part of its ROP... - February 24th, 2025
- Prevent Blindness Kicks Off Second Annual Retinopathy of Prematurity Awareness Week - Vision Monday - February 24th, 2025
- Gene therapy for rare childhood blindness shows lasting vision gains - R&D World - February 24th, 2025
- The Murder Capital's Blindness: A Voice of Significance in an Era Craving Authentic Discourse - Indie Is Not A Genre - February 24th, 2025
- Albums Of The Week: The Murder Capital | Blindness - Tinnitist - February 24th, 2025
- After Maine native testifies before Congress, Elon Musk targets his disability - Press Herald - February 24th, 2025
- Ozempic could BLIND you - it damages veins in the eye, major study finds - Daily Mail - February 24th, 2025
- Cerebral Venous Thrombosis Presenting With Binocular Blindness and Bilateral Sensorineural Hearing Loss - Cureus - February 24th, 2025
- Treatment for horses may lead to therapy for type of blindness - Mid Florida Newspapers - February 24th, 2025
- The Murder Capital: Blindness album review - Louder Than War - February 24th, 2025
- 'First in the world': London doctors cure blindness in children born with a genetic condition - WION - February 24th, 2025
- Doctors cure rare blindness in infants with gene therapy - NewsBytes - February 24th, 2025
- Gene therapy new trial treats rare blindness in children - Daily Jang - February 24th, 2025
- Ozempic Blindness Could Be Rare but Real: What Experts Say About the Risk - ZME Science - February 24th, 2025
- Parents of boy with rare eye condition hail amazing results of gene therapy - Yahoo News UK - February 24th, 2025
- Myths and Assumptions about Blindness - BBC.com - February 24th, 2025
- Man accused of beating victim, causing permanent blindness in one eye - KAIT - February 15th, 2025
- Scientists Find Link Between Weight Loss Drugs and Blindness - AOL - February 15th, 2025
- Treatment for horses may lead to therapy for type of blindness - University of Florida - February 15th, 2025
- How Ageism Impacts Adults with Low Vision - National Council on Aging - February 15th, 2025
- Ozempic and other weight loss drugs may be linked to conditions that could lead to blindness, study says - Quartz - February 15th, 2025
- Treatment for horses may lead to therapy for type of blindness - Phys.org - February 15th, 2025
- Treatment for Horses May Lead to Therapy for Type of Blindness - Morning Ag Clips - - February 15th, 2025
- Foundation Fighting Blindness Celebrates 20 Years of VisionWalk - PR Newswire - February 15th, 2025
- Woman Victim of 'Lash Blindness'Shock at How She Looks Without Them - Newsweek - February 15th, 2025
- Some Ozempic users are losing their vision - but scientists dont know why - The Independent - February 15th, 2025
- Those with visual impairments or blindness tackling the trails at Pico Mountain - WCAX - February 15th, 2025
- Prevent Blindness Issues Call for Nominations for the 2025 Jenny Pomeroy Award for Excellence in Vision and Public Health, and Rising Visionary Award... - February 15th, 2025
- Medical warning: Ozempic and Mounjaro may be linked to vision loss - India Today - February 15th, 2025
- New research links Ozempic to vision loss and risk of blindness - MSN - February 15th, 2025
- Ozempic Blindness: Weight Loss Drugs Linked to This Condition, Experts Warn - Tech Times - February 15th, 2025
- Ozempic Blindness Lawsuit Mounts: Shocking Side Effect Of Weight Loss Drug Is 'Eye Stroke,' What You Need To Know - IBTimes UK - February 15th, 2025
- The Politics Of Erasure: Gaza, Genocide, And The Wests Wilful Blindness OpEd - Eurasia Review - February 15th, 2025
- WHO launches new initiative to tackle the main cause of vision impairment - December 19th, 2024
- Blindness Advocates on Why There Should Be Audio Description Oscars - Variety - December 19th, 2024
- Diabetic retinopathy is treatable and preventable but only if you catch it in time - USA TODAY - December 19th, 2024
- AI: Could it help prevent blindness in diabetics? - BBC.com - December 19th, 2024
- Health Officials Investigate Rare Form of Blindness Tied to Ozempic - Gizmodo - December 19th, 2024
- Ozempic Could Be Blinding People Trying to Lose Weight - VICE - December 19th, 2024
- What is retinitis pigmentosathe vision disorder in the movie Blink? - National Geographic - December 19th, 2024
- VR shows promise in aiding navigation of people with blindness or low vision - Health Tech World - December 19th, 2024
- Ozempic could be linked to a common cause of sudden blindness, study finds - Quartz - December 19th, 2024
- New virtual realitytested system shows promise in aiding navigation of people with blindness or low vision - Tech Xplore - December 19th, 2024
- Ex-meth user who gouged her own eyeballs out while high says she is happier years after nightmarish episode - New York Post - December 19th, 2024
- Officials investigating link between Ozempic and eye-rotting disease that makes people blind - Daily Mail - December 19th, 2024
- Youngster to 'have eye removed' after minor fall - but NHS waitlist 'over 3 years' - NationalWorld - December 19th, 2024
- Restoring Vision: The Promise of Stem Cells in Healing Blindness - This is Local London - December 19th, 2024
- COAVS and Fred Hollows Foundation strengthen efforts to combat blindness in Pakistan - 24newshd - December 19th, 2024
- Study finds link between Ozempic and increased risk of vision loss - The Express Tribune - December 19th, 2024
- Going blind at 33 is devastating I wont see my childrens faces as they grow up - The Telegraph - December 19th, 2024
- Europol terror report reveals stark blindness about where the danger lies - Gript - December 19th, 2024
- Elton John lost his vision; signs and symptoms of eye infections that can cause blindness - The Times of India - December 6th, 2024
- Elton John's battle with blindness: How 77-year-old star's husband David Furnish guided him around premiere as - Daily Mail - December 6th, 2024
- Experimental study shows connection between COVID infection and age-related blindness - Medical Xpress - December 6th, 2024
- Elton John confirms shocking blindness after severe infection fight: I havent been able to see.. - Hindustan Times - December 6th, 2024
- Yes, an Eye Infection *Can* Lead To Vision Loss Heres How - Katie Couric Media - December 6th, 2024
- Elton John Battling Partial Blindness After Serious Eye Infection - Digital Music News - December 6th, 2024
- CU Anschutz researchers working to cure blindness through total eye transplantation - 9News.com KUSA - December 6th, 2024
- Elton John lost his vision from an eye infection. Here's why that might happenand how to prevent it - Fortune - December 6th, 2024
- Elton John announces blindness due to infection - CBS19.tv KYTX - December 6th, 2024
- David Frost: I suffer from face blindness. As a politician, being unable to identify people is agony - The Telegraph - December 6th, 2024
- Hes still standing how Elton John has survived far worse than blindness - The Telegraph - December 6th, 2024
- Foundation Fighting Blindness Partners with University of Colorado Anschutz Medical Campus and Other Leading Institutions to Secure Up to $46 Million... - December 6th, 2024
- Walmart helping low vison and blind customers shop with new app - KSLA - December 6th, 2024
- Elton John Says He Is Blind In The Right Eye Due to An Infection; What Is It All About? - Times Now - December 6th, 2024
- Trumps Win: The Blindness of Republicans and Democrats - The Times of Israel - December 6th, 2024