declining eyesight Archives - Amazing Health Advances

Eye Cells “Rewire” Themselves When Vision Begins to Fail

The AHA! Team — Mon, 14 Jul 2025 05:19:44 +0000

University of California, Los Angeles (UCLA), Health Sciences via Newswise – Mouse study reveals how retinal neurons adapt by forming new connections during early stages of inherited blindness Retinal cells can rewire themselves Scientists at the Jules Stein Eye Institute at the David Geffen School of Medicine at UCLA have discovered that certain retinal cells can rewire themselves when vision begins to deteriorate in retinitis pigmentosa, a genetic eye disease that leads to progressive blindness. In a study using mouse models, researchers found that rod bipolar cells, neurons that normally receive signals from rods that provide night vision, can form new functional connections with cones that provide daytime vision when their usual partners stop working. The study appears in Current Biology. Why it matters Retinitis pigmentosa affects millions of people worldwide and is a leading cause of inherited blindness. While the disease often progresses slowly, with some patients maintaining a surprising amount of usable vision into middle age, little is known about how retinal circuits adapt to cell loss. Understanding these natural adaptation mechanisms could reveal new targets for treatments aimed at preserving vision. What the study did Researchers used rhodopsin knockout mice that model early retinitis pigmentosa, where rod cells cannot respond to light and degeneration proceeds slowly. They made electrical recordings from individual rod bipolar cells, neurons that normally connect to rods, to see how these cells behaved when their usual input was lost. The team also used additional mouse models lacking different components of rod signaling to determine what triggers the rewiring process. They supported their single-cell findings with whole-retina electrical measurements. What they found Rod bipolar cells in mice lacking functional rods showed large-amplitude responses driven by cone cells instead of their normal rod inputs. These rewired responses were strong and had the expected electrical characteristics of cone-driven signals. The rewiring occurred specifically in mice with rod degeneration, but not in other mouse models that lacked rod light responses without actual cell death. This suggests that the cellular rewiring is triggered by the degeneration process itself, rather than simply the absence of light responses or broken synapses. The findings complement the research team’s previous 2023 work showing that individual cone cells can remain functional even after severe structural changes in later disease stages. Together, these studies reveal that retinal circuits maintain function through different adaptation mechanisms at various stages of disease progression. The research shows that retinal adaptation occurs through different mechanisms at various disease stages, which could help scientists identify new targets for preserving vision in patients with inherited retinal diseases. From the experts “Our findings show that the retina adapts to the loss of rods in ways that attempt to preserve daytime light sensitivity in the retina,” said senior author A.P. Sampath, PhD of the UCLA Stein Eye Institute. “When the usual connections between rod bipolar cells and rods are lost, these cells can rewire themselves to receive signals from cones instead. The signal for this plasticity appears to be degeneration itself, perhaps through the role of glial support cells or factors released by dying cells.” What’s next One of the open questions is whether this rewiring represents a general mechanism used by the retina when rods die. The group is currently exploring this possibility with other mutant mice that carry mutations to rhodopsin and other rod proteins that are known to cause retinitis pigmentosa in humans. About the study Published in Current Biology (2025). “Photoreceptor degeneration induces homeostatic rewiring of rod bipolar cells.” DOI: 10.1016/j.cub.2025.05.057 About the Research Team Paul J. Bonezzi, Rikard Frederiksen, Annabelle N. Tran, Kyle Kim, Gordon L. Fain, and Alapakkam P. Sampath from the Department of Ophthalmology, Stein Eye Institute, David Geffen School of Medicine at UCLA. Paul J. Bonezzi and Rikard Frederiksen contributed equally to this work. Funding and Disclosures This work was supported by the National Eye Institute of the National Institutes of Health USA (EY36811 and EY01844) and an unrestricted grant by Research to Prevent Blindness to the UCLA Department of Ophthalmology. The authors have no disclosures. To read the original article click here.

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New Drug Shows Promise in Restoring Vision for People with Nerve Damage

The AHA! Team — Fri, 04 Apr 2025 05:24:11 +0000

University of Colorado Anschutz Medical Campus via EurekAlert! – Research from the University of Colorado Anschutz Medical Campus reveals drug could potentially help repair vision in those with multiple sclerosis (MS) and other neurological conditions. Researchers at the University of Colorado Anschutz Medical Campus have found a promising drug candidate that could help restore vision in individuals with multiple sclerosis (MS) and other neurological conditions that damage neurons. The study was published this week in the journal Nature Communications. The drug, LL-341070, enhances the brain’s ability to repair damaged myelin— the protective sheath around nerve fibers. Damage to myelin is a hallmark of diseases like MS, as well as a natural consequence of aging, often resulting in vision loss, loss of motor skills, and cognitive decline. The research, focused on vision, demonstrated that while the brain has some ability to repair itself when myelin is damaged, the process can be slow and inefficient. Researchers observed that LL-341070 significantly accelerated the repair process and improved brain function related to vision in mice, even after severe damage. “This research brings us closer to a world where the brain has the capacity to heal itself” “This research brings us closer to a world where the brain has the capacity to heal itself” said Ethan Hughes, PhD, co-lead author and associate professor in the Department of Cell and Developmental Biology at the CU School of Medicine. “By harnessing this potential, we hope to help people with diseases like MS by potentially reversing some of the damage, offering people the opportunity to regain their vision and cognitive function.” Researchers discovered that the treatment makes the repair process is much more effective following serious damage, highlighting the importance of intervention with severe injury. Even partial repair of myelin was found to significantly improve vision-related brain functions. “We’ve known for years that myelin plays a crucial role in brain function” “We’ve known for years that myelin plays a crucial role in brain function,” said Daniel Denman, PhD, co-lead author of the study and assistant professor in the Department of Physiology and Biophysics at the CU School of Medicine. “This study highlights the role of cortical myelin in visual function. The drug could be a game-changer because it accelerates the brain’s natural repair mechanisms.” The researchers plan to test the drug in other areas of the brain and refine the treatment, hoping to make it even more effective and eventually accessible to patients. “This discovery is just the beginning,” Hughes said. “We are optimistic that LL-341070 and similar therapies could one day provide real, tangible benefits to patients by improving overall brain function and quality of life.” About the University of Colorado Anschutz Medical Campus The University of Colorado Anschutz Medical Campus is a world-class medical destination at the forefront of transformative science, medicine, education and patient care. The campus encompasses the University of Colorado health professional schools, more than 60 centers and institutes and two nationally ranked independent hospitals – UCHealth University of Colorado Hospital and Children’s Hospital Colorado – which see more than two million adult and pediatric patient visits yearly. Innovative, interconnected and highly collaborative, the CU Anschutz Medical Campus delivers life-changing treatments, patient care and professional training and conducts world-renowned research fueled by $910 million in annual research funding, including $757 million in sponsored awards and $153 million in philanthropic gifts. Journal Nature Communications To read the original article click here.

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Morning Exposure to Deep Red Light Improves Declining Eyesight

AHA Publisher — Fri, 03 Dec 2021 08:00:11 +0000

University College London via Newswise – Just three minutes of exposure to deep red light once a week, when delivered in the morning, can significantly improve declining eyesight, finds a pioneering new study by UCL researchers. Published in Scientific Reports, the study builds on the team’s previous work*, which showed daily three-minute exposure to longwave deep red light ‘switched on’ energy producing mitochondria cells in the human retina, helping boost naturally declining vision. For this latest study, scientists wanted to establish what effect a single three-minute exposure would have, while also using much lower energy levels than their previous studies. Furthermore, building on separate UCL research in flies** that found mitochondria display ‘shifting workloads’ depending on the time of day, the team compared morning exposure to afternoon exposure. In summary, researchers found there was, on average, a 17% improvement in participants’ colour contrast vision when exposed to three minutes of 670 nanometre (long wavelength) deep red light in the morning and the effects of this single exposure lasted for at least a week. However, when the same test was conducted in the afternoon, no improvement was seen. Scientists say the benefits of deep red light, highlighted by the findings, mark a breakthrough for eye health and should lead to affordable home-based eye therapies, helping the millions of people globally with naturally declining vision. Lead author, Professor Glen Jeffery (UCL Institute of Ophthalmology), said: “We demonstrate that one single exposure to long wave deep red light in the morning can significantly improve declining vision, which is a major health and wellbeing issue, affecting millions of people globally. “This simple intervention applied at the population level would significantly impact on quality of life as people age and would likely result in reduced social costs that arise from problems associated with reduced vision.” Naturally Declining Vision and Mitochondria In humans around 40 years old, cells in the eye’s retina begin to age, and the pace of this ageing is caused, in part, when the cell’s mitochondria, whose role is to produce energy (known as ATP) and boost cell function, also start to decline. Mitochondrial density is greatest in the retina’s photoreceptor cells, which have high energy demands. As a result, the retina ages faster than other organs, with a 70% ATP reduction over life, causing a significant decline in photoreceptor function as they lack the energy to perform their normal role. In studying the effects of deep red light in humans, researchers built on their previous findings in mice, bumblebees and fruit flies, which all found significant improvements in the function of the retina’s photoreceptors when their eyes were exposed to 670 nanometre (long wavelength) deep red light. “Mitochondria have specific sensitivities to long wavelength light influencing their performance: longer wavelengths spanning 650 to 900nm improve mitochondrial performance to increase energy production,” said Professor Jeffery. Morning and Afternoon Studies The retina’s photoreceptor population is formed of cones, which mediate colour vision, and rods, which adapt vision in low/dim light. This study focused on cones*** and observed colour contrast sensitivity, along the protan axis (measuring red-green contrast) and the tritan axis (blue-yellow). All the participants were aged between 34 and 70, had no ocular disease, completed a questionnaire regarding eye health prior to testing, and had normal colour vision (cone function). This was assessed using a ‘Chroma Test’: identifying coloured letters that had very low contrast and appeared increasingly blurred, a process called colour contrast. Using a provided LED device all 20 participants (13 female and 7 male) were exposed to three minutes of 670nm deep red light in the morning between 8am and 9am. Their colour vision was then tested again three hours post exposure and 10 of the participants were also tested one week post exposure. On average there was a ‘significant’ 17% improvement in colour vision, which lasted a week in tested participants; in some older participants there was a 20% improvement, also lasting a week. A few months on from the first test (ensuring any positive effects of the deep red light had been ‘washed out’) six (three female, three male) of the 20 participants, carried out the same test in the afternoon, between 12pm to 1pm. When participants then had their colour vision tested again, it showed zero improvement. Professor Jeffery said: “Using a simple LED device once a week, recharges the energy system that has declined in the retina cells, rather like re-charging a battery. “And morning exposure is absolutely key to achieving improvements in declining vision: as we have previously seen in flies, mitochondria have shifting work patterns and do not respond in the same way to light in the afternoon – this study confirms this.” For this study the light energy emitted by the LED torch was just 8mW/cm2, rather than 40mW/cm2, which they had previously used. This has the effect of dimming the light but does not affect the wavelength. While both energy levels are perfectly safe for the human eye, reducing the energy further is an additional benefit. Home-Based Affordable Eye Therapies With a paucity of affordable deep red-light eye-therapies available, Professor Jeffery has been working for no commercial gain with Planet Lighting UK, a small company in Wales and others, with the aim of producing 670nm infra-red eye ware at an affordable cost, in contrast to some other LED devices designed to improve vision available in the US for over $20,000. “The technology is simple and very safe; the energy delivered by 670nm long wave light is not that much greater than that found in natural environmental light,” Professor Jeffery said. “Given its simplicity, I am confident an easy-to-use device can be made available at an affordable cost to the general public. “In the near future, a once a week three-minute exposure to deep red light could be done while making a coffee, or on the commute listening to a podcast, and such a simple addition could transform eye care and vision around the world.” To read the original article click here.

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