New type of omega-3 could prevent visual decline associated Alzheimer’s and other diseases

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A new form of the omega-3 fatty acid docosahexaenoic acid (DHA), has been developed that is able to cross into the eye’s retina to stave off the visual declines related to Alzheimer’s, diabetes and other diseases.

The DHA found in fish oil capsules and other supplements is usually in a form called triacylglycerol (TAG) DHA. TAG-DHA has benefits in other areas of the body, however, it does not reach the eyes on account of the fact that it cannot traverse from the bloodstream into the retina. For this study, researchers created a new lysophospholipid form of DHA, or LPC-DHA. Using mice, LPC-DHA successfully increased DHA in the retina and reduced eye problems associated with Alzheimer’s-like processes.

“Dietary LPC-DHA is enormously superior to TAG-DHA in enriching retinal DHA and could be potentially beneficial for various retinopathies in patients,” said Sugasini Dhavamani, a research assistant professor in the Department of Medicine at the University of Illinois at Chicago. “This approach provides a novel therapeutic approach for the prevention or mitigation of retinal dysfunction associated with Alzheimer’s disease and diabetes.”

Dhavamani will present the research at Discover BMB, the annual meeting of the American Society for Biochemistry and Molecular Biology, March 25-28 in Seattle.

In healthy eyes, DHA is concentrated in the retina, where it helps maintain photoreceptors, the cells that convert light into signals that are sent to the brain. When there is a DHA deficiency in the retina it is usually associated with vision loss. People with Alzheimer’s disease, as well as those with diabetes, retinitis pigmentosa, age-related macular degeneration and peroxisomal disorders, frequently have abnormally low levels of retinal DHA, and as a result visual impairments are common.

While boosting DHA can help to prevent such declines, increasing retinal DHA content has been a challenge with the supplements currently available. Here’s the issue: for a dietary supplement to effectively deliver DHA to the retina, the DHA must be able to first be absorbed from the intestine into the bloodstream and then cross from the bloodstream into the retina in an amount that will be beneficial to the patient.

“Increasing the retinal DHA at clinically feasible doses has not been possible until now because of the specificity of the blood-retinal barrier that is incompatible with the specificity of the intestinal barrier,” said Dhavamani. “This study uses the novel approach of dietary LPC-DHA that overcomes both intestinal and blood-retinal barriers and improves retinal function.”

The researchers tested their LPC-DHA supplement in mice bred to exhibit processes similar to those found in early-onset Alzheimer’s disease. After six months, mice that were fed LPC-DHA daily showed a 96% improvement in retinal DHA content and preserved retinal structure and function. In contrast, TAG-DHA supplements had no effect on retinal DHA levels or function.

The results suggest that LPC-DHA supplements could help to prevent Alzheimer’s-related declines in visual function. Researchers believe this approach should also be helpful for other disorders in which DHA deficiency and vision impairment are common.

The dosage of LPC-DHA used in the study is equivalent to about 250 to 500 milligrams of omega-3 fatty acids per day in humans. Because these studies were conducted in mice, additional studies would be need to be conducted to confirm that LPC-DHA is safe and effective for use in humans.

LED Contact Lenses to Treat Diabetic Retinopathy

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Diabetes is a long-term chronic disease with many complications, the longer a patient suffers from diabetes, the higher the risk of developing retinopathy which can gradually lead to a decline in vision and even to blindness.

A POSTECH research team led by Professor Sei Kwang Hahn and Ph.D. candidate Geon-Hui Lee (Department of Materials Science and Engineering) in collaboration with Dr. Sangbaie Shin of PHI BIOMED Co. has recently developed a smart contact lens-type wearable device to prevent diabetic retinopathy and treat it in its early stages by irradiating 120 µW far red/LED light to the retina. This technology for smart LED contact lens has attracted a great deal of attention for various ophthalmologic diseases.

The current treatment options for Diabetic retinopathy are highly invasive repeated therapeutic injections to the eyeball or thousands of small burns made with a laser to destroy capillaries near the edges of retina under anesthesia. Both procedures are considered highly painful for the patient, so not ideal.

Diabetic RetinopathyThrough the study with diabetic animal, the researchers confirmed that the diabetic retinopathy did not appear in animals that wore the smart contact lenses for 15 minutes 3 times a week for a total of 8 weeks. In contrast, the animals that did not wear the lenses showed retinopathic conditions. The safety and effectiveness of the lenses were also confirmed by the histological analysis of the cornea and retina.

“This study has demonstrated the feasibility of a lens-type wearable device for the applications not only to monitoring oxygen saturation, heart beating rate, and ophthalmologic diseases, but also to treating depression, insomnia, neuronal diseases and more,” remarked Professor Sei Kwang Han who led the study.

So the future is looking bright indeed for not only diabetics, but suffers of depression, insomnia and many other conditions.

Vision Gains for Retinal Vein Occlusion Patients

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Retinal vein occlusion is one of the most common blinding conditions in the United States; without treatment, central retinal vein occlusion (CRVO), the most severe type of retinal vein occlusion often leads to significant and permanent vision loss. New research shows that a treatment for retinal vein occlusion yields long-lasting vision gains, with visual acuity remaining significantly above baseline at five years. However, many patients require ongoing treatment.  A report on five-year outcomes of the Study of Comparative Treatments for Retinal Vein Occlusion 2 (SCORE2), was published April 21 in American Journal of Ophthalmology. SCORE2 was funded in part by the National Eye Institute (NEI), a part of the National Institutes of Health.

Retinal Vein OcclusionRetinal vein occlusion is caused by a blockage of the veins carrying blood away from the retina, the light-sensitive tissue at the back of the eye. This blockage can lead to macular edema where fluid becomes trapped within and under the retina, leading to rapid and severe loss of visual acuity. Without treatment, this condition typically leads to permanent loss of vision. The most effective treatment, injections of anti- vascular endothelial growth factor (VEGF) drugs, helps control blood vessel leakage and swelling in the retina.

“While anti-VEGF therapy is associated with significant improvement in both retinal swelling and visual acuity in patients with central or hemi-retinal vein occlusion, our findings show that most of the patients followed still required treatment to control the macular edema for at least five years,” said Ingrid U. Scott, M.D., M.P.H., Penn State College of Medicine, Hershey, chair of the study. “This demonstrates the importance of continued monitoring of these patients.”

In 2017, SCORE2 clinical trial investigators reported that two types of anti-VEGF treatment were equally effective at improving visual acuity in people with macular edema due to CRVO or hemi-retinal vein occlusion (HRVO). CRVO affects the entire retina, while HRVO generally affects about half of the retina. Half of the study participants had been given Avastin (bevacizumab) while the other half received Eylea (aflibercept). At the six-month mark, the vision of participants in both groups had, on average, improved over three lines on an eye chart.

At five years, many participants in both groups had lost some visual acuity when compared to their acuity at the 6 and 12-month marks; however, they retained on average three lines of improvement, compared to their acuity at the beginning of the study.

“It was surprising to us that despite many participants still needing treatment after five years, their visual acuity outcome remained very good,” said Michael Ip, M.D., co-chair of the study from Doheny Eye Institute, University of California Los Angeles. “In comparison to this treatment for wet age-related macular degeneration, where initial vision improvements fade over time, these results are quite favorable.”

“This five-year study tells us a lot about what’s happening with retinal vein occlusion patients in the real world,” said Scott. “Prior to this study, retinal vein occlusion was widely considered an acute illness. This study shows that RVO is a chronic disease. It also underscores the importance of disease monitoring and individualized treatment to achieve the best possible vision.”

“The SCORE2 study provides invaluable data to guide clinicians and their patients toward informed decisions regarding treatment for retinal vein occlusion,” said NEI Director Michael F. Chiang, M.D.

To read the original article click here: https://www.sciencedaily.com/releases/2022/04/220421105507.htm

I thought you looked familiar…

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In a recent study led by Cedars-Sinai, researchers have found new information about how the part of the brain responsible for memory is activated when the eyes come to rest on a face versus another object or image. Their findings, which were published in the peer-reviewed journal Science Advances, add to already established scientific understanding of how memory works, and to evidence supporting a future treatment targeted for memory disorders.

While vision feels continuous, people move their eyes from one distinct spot to another three to four times per second. In this study, researchers found that when the eyes land on a face, certain cells in the amygdala, a part of the brain that processes social information, react and trigger memory-making activity.

“You could easily argue that faces are one of the most important objects we look at,” said Ueli Rutishauser, PhD, director of the Center for Neural Science and Medicine at Cedars-Sinai and senior author of the study. “We make a lot of highly significant decisions based on looking at faces, including whether we trust somebody, whether the other person is happy or angry, or whether we have seen this person before.”

The study was conducted using 13 epileptic patients who had electrodes implanted in their brains and were then shown images varying from human faces to geometric figures to cars to flowers while having a camera trained on their eyes to determine what they were looking at.  In addition the researchers also recorded the patient’s theta wave activity.  Theta waves are a distinct electrical brain wave that is created in the hippocampus and they are key in processing information and forming memories.

Researchers showed the patients the images in two sessions and found that each time the participants’ eyes landed on a human face, certain cells in the amygdala fired. Every time these “Face Cells” fired the pattern of theta waves in the hippocampus reset or restarted.

Vision and Faces“We think that this is a reflection of the amygdala preparing the hippocampus to receive new socially relevant information that will be important to remember,” said Rutishauser, the Board of Governors Chair in Neurosciences and a professor of Neurosurgery and Biomedical Sciences.

Interestingly, the researchers showed that the more quickly a subject’s face cells fired when their eyes fixed on a face, the more apt the subject was to remember that face. When a subject’s face cells fired more slowly, they were more likely to forget the face they had seen.

Subjects’ face cells also fired more slowly when they were shown faces they had seen before, suggesting those faces were already stored in memory and the hippocampus didn’t need to be activated.

Rutishauser said these results suggest that people who struggle to remember faces could have a dysfunction in their amygdala, noting that this type of dysfunction has been implicated in disorders related to social cognition, such as autism.

The results also indicate the importance of both eye movements and theta waves in the memory process, Rutishauser said.

To read the original article click here: https://www.sciencedaily.com/releases/2022/03/220318161429.htm

Could diet be the cause of vision loss in seniors?

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It’s possible that diets heavy in red meat and fatty foods may help spur a leading cause of vision loss in older Americans, according to new research.

A recent study found that people who ate a more typical Western diet were three times more likely to develop late-stage age-related macular degeneration.

“What you eat seems to be important to your vision, and whether or not you have vision loss later in life,” said study lead author Amy Millen. She’s an associate professor in the department of epidemiology and environmental health at the University at Buffalo’s School of Public Health and Health Professions, in Buffalo, N.Y.

“People know that diet influences cardiovascular risk and the risk of obesity, but the public may not know that diet can affect vision loss,” Millen said.

Age-related macular degeneration occurs when a part of the eye called the macula is damaged. Sometimes this happens when deposits called drusen grow on the macula. Or it can occur when new blood vessels continue to form and leak blood, scarring the macula, according to the American Academy of Ophthalmology.

Genetics and smoking are known risk factors for age-related macular degeneration.

This study included almost 1,300 people from a nationally representative sample. Most did not have macular degeneration. There were 117 who had early AMD, and 27 had late.

All of the study participants completed surveys about their diets twice during the 18-year study.

The researchers sorted the foods into 29 categories to measure the quality of the diet.

They found that people who ate a more Western diet were much more likely to develop late-stage AMD. Foods linked to a higher risk included:

  • Red and processed meats
  • Fats, such as margarine and butter
  • High-fat dairy
  • Fried foods.

In short the observational study showed a diet high in fatty foods, processed meats and refined grains makes the more severe form of macular degeneration more likely.

It is not known if you can make up for a lifetime of eating poorly. But a healthy diet — full of vegetables, especially dark, leafy greens, and fruits and fatty fish — contains important nutrients for eye health, including lutein and zeaxanthin.

The study was published in the December issue of the British Journal of Ophthalmology.

To read the original article click here (Fatty diet linked to leading cause of vision loss in seniors)

New hope for those affected by thyroid eye disease

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The newly approved drug teprotumumab can offer hope to adults with thyroid eye disease, a rare and potentially blinding condition.

It’s the first treatment specifically approved for thyroid eye disease. The drug was approved Tuesday, January 11, 2020 by the U.S. Food and Drug Administration. It will be marketed under the brand name Tepezza.

“This may be a drug that offers a new approach and a paradigm shift,” said Dr. Raymond Douglas, lead author of a study the FDA considered when making its final decision. “Currently, we use supportive therapy for people with thyroid eye disease, but their quality of life is diminished by their symptoms.

“Teprotumumab was extraordinarily effective. We hope that people with thyroid eye disease won’t have to suffer as they have in the past. With treatment, they’re not going to be blind. They’re not going to be disfigured. They can even watch their kids playing soccer when it’s windy,” Douglas explained. Without treatment, wind could be too drying to the eyes.

Thyroid eye disease causes inflammation in the back of the eye causing the eyes to bulge. The swelling may also squeeze the optic nerve, causing vision problems, said Douglas, a professor of surgery in the division of ophthalmology at Cedars-Sinai Medical Center in Los Angeles.

Thyroid eye disease typically develops in people with an overactive thyroid gland caused by Graves’ disease. Redness, swelling and a gritty feeling in the eyes are also classic symptoms, the American Thyroid Association says. Other conditions that can occur include dry eyes or excessive tearing, double vision and sensitivity to light. The most noticeable symptom, however, is the bulging of the eyes, and it may be difficult to completely close the eyes.

Because thyroid eye disease is rare, the FDA gave this drug “orphan drug” status. This means companies are provided incentives to encourage the development of drugs for rare diseases. The medication was also given the FDA’s priority review, fast track and breakthrough therapy designations to assist the manufacturer in bringing the drug to market.

The drug’s approval was based on results of two studies that included 170 people with active thyroid disease. The drug was administered intravenously once every week for three weeks over a 21-week period. Douglas said the IV infusions take about an hour.

Teprotumumab started working after just two doses, Douglas said. After 24 weeks, 83 percent of people on the drug had a measurable reduction in eye bulge — more than 2 millimeters — versus just 10 percent of those on a placebo.

The overall response rate was 78 percent among those taking the drug compared to 7 percent of people taking a placebo. Quality of life was much higher for people taking the drug, the study found.

Douglas said treatment with the drug reversed double vision as well as surgery does.

Side effects were minimal and well-tolerated, according to Douglas. Some of the more common side effects included muscle cramps, nausea, hair loss and fatigue. The drug should not be used in pregnancy.

Learn more about thyroid eye disease from the American Thyroid Association.

 To read the original article, click here (New drug may stop blindness from thyroid eye disease)

Can cadavers help restore vision to the blind?

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This may not be as far-fetched as it sounds. According to an article published Thursday, January 14, 2021 by Stem Cell Reports, retinal stem cells collected from human cadavers may offer a potential treatment for blindness.

When healthy retinal pigment epithelium cells were implanted under the macula of blind monkeys, at least some vision was restored without serious side effects, the study’s researchers from the Mount Sinai School of Medicine in New York City said. (The retinal pigment epithelium is a layer of pigmented cells in the retina and the macula is the central part of the retina.)

The transplanted cells (harvested from human cadavers) effectively took over the function of the monkeys’ natural retinal pigment epithelium, enabling them to see, according to the researchers.

The study’s co-author Timothy Blenkinsop, assistant professor of cell, developmental and regenerative biology at the Icahn School of Medicine at Mount Sinai, said this in a statement:

“We have demonstrated that [donor cells] at least partially replace function in the macula of a non-human primate, human cadaver donor-derived cells can be safely transplanted underneath the retina and replace host function, and therefore may be a promising source for rescuing vision in patients with retina diseases.”

Retinal pigment epithelium dysfunction can lead to eye disorders such as macular degeneration, causing vision loss and blindness, which affects about 200 million people worldwide.

Using cadaver donor eyes can help ensure donor cells match well with recipients, and can serve as a recurring source of human retinal pigment epithelium cells.

These retinal pigment epithelium “patches,” or small quantities of collected cells, transplanted under the primates’ maculas remained “stable and integrated” for at least three months, without serious side effects such as immune-system rejection or light sensitivity. This is quite encouraging.

Additionally, the transplanted cells worked well with the existing retinal pigment epithelium to support the existing photoreceptors in their eyes, which aids with light absorption, among other functions.

Transplantation of retinal pigment epithelium stem cells derived from human adult cadaver eyes could serve as a possible treatment for macular degeneration, the study suggests.

However, the researcher stress that additional research on this approach is necessary to explore whether stem cells derived from cadaver adult eyes can restore vision in human patients.

“The results of this study suggest human adult donor retinal pigment epithelium is safe to transplant, strengthening the argument for human clinical trials for treating retina disease,” Blenkinsop said.

To read the original article click here. (Retinal stem cells from cadavers may help restore vision in blind, study finds – UPI.com)

Could following the Mediterranean diet prevent blindness?

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The evidence is in and it shows that a poor diet plays a big role in the development of age-related macular degeneration (AMD), a leading cause of blindness in the US.  A large collaboration of researchers from the EU investigated the connection between genes and lifestyle on the development of AMD has found that people who followed a Mediterranean diet cut their risk of late-stage AMD by 41% This research expanded on previous studies and suggests that such a diet is beneficial for everyone, whether you already have the disease or are at risk of developing it.

A Mediterranean diet emphasizes eating less meat and more fish, vegetables, fruits, legumes, unrefined grains, and olive oil. Previous research had linked it to a longer lifespan and a reduced incidence of heart disease and cognitive decline. Previous studies also showed following this diet can help with certain types of AMD, but only focused on different stages of the disease.

By combining this earlier research on AMD with the latest data, a clear picture emerges: Diet has the potential to prevent a blinding disease.

AMD is a degenerative eye disease. It causes loss of central vision, which is crucial for simple everyday activities, such as the ability to see faces, drive, read, and write. It’s a leading cause of vision loss among people age 50 and older, affecting 1.8 million Americans. By 2020, that number is expected to climb to nearly 3 million.

In this study, researchers analyzed food-frequency questionnaires from nearly 5,000 people who participated in two previous investigations — the Rotterdam Study, which evaluated disease risk in people age 55 and older, and the Alienor Study, which assessed the association between eye diseases and nutritional factors in people aged 73 and older. Patients in the Rotterdam study were examined and completed food questionnaires every five years over a 21-year period, while patients in the Alienor Study were seen every two years over a 4-year period. The researchers found that those who closely followed the diet were 41%  less likely to develop AMD compared with those who did not follow the diet.

They also found that none of the individual components of a Mediterranean diet on their own — fish, fruit, vegetables, etc. — lowered the risk of AMD. Rather, it was the entire pattern of eating a nutrient-rich diet that significantly reduced the risk of late AMD.

There are two kinds of AMD — dry and wet. The dry type affects about 80 to 90 percent of people with AMD. In dry AMD, small white or yellowish deposits, called drusen, form on the retina, causing it to deteriorate over time. In the wet form, blood vessels grow under the retina and leak. While there is an effective treatment available for the wet type, there is no treatment available for dry AMD.

So remember you are what you eat!

To read the original article in its entirety, click here. https://www.sciencedaily.com/releases/2018/10/181001101940.htm

Biomarkers could aid in early detection of glaucoma

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Researchers bred mice in which the gene PTP-Meg2 (protein tyrosine phosphatase megakaryocyte 2) was mutated. As a result, the animals suffered from chronic intraocular pressure elevation. The research team successfully demonstrated that, in their model, the intraocular pressure elevation was associated with a loss of optic nerve fibers and retinal cells. They also observed that retinal cells were unable to function properly. They further discovered glial cells and certain components of the immune system showed a reaction in the animals’ optic nerve and retina. As both aspects may be relevant for neurodegeneration, specific and early intervention into these cellular mechanisms could inhibit glaucoma.

By making use of a genetic screening, the researchers identified new potential biomarkers for glaucoma, which in the future, may facilitate early detection. As a result, it will be possible to start therapy at an earlier stage, before the optic nerve and retina are damaged. The glaucoma-mouse model may, moreover, be used to test new therapy options. So far intraocular pressure was reduced and nerve cells were retained in the mice if they were given a drug that has been used to treat human patients.

With more than 60 million patients, Glaucoma is a leading cause of blindness worldwide. In Germany alone, there are one million patients — and the estimated number of unknown cases is likely to be much higher, due to the fact that symptoms often remain undetected during the early stage of the disease. In glaucoma patients, the optic nerve and the retinal nerve cells are damaged beyond repair.

To read the original article in its entirety, click here. https://www.sciencedaily.com/releases/2018/10/181025103308.htm

AMAZING: Congenital blindness reversed in mice!

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Researchers funded by the National Eye Institute (NEI) have reversed congenital blindness in mice by changing supportive cells in the retina called Müller glia into rod photoreceptors. The findings advance efforts toward regenerative therapies for blinding diseases such as age-related macular degeneration and retinitis pigmentosa.

“This is the first report of scientists reprogramming Müller glia to become functional rod photoreceptors in the mammalian retina,” said Thomas N. Greenwell, Ph.D., NEI program director for retinal neuroscience. “Rods allow us to see in low light, but they may also help preserve cone photoreceptors, which are important for color vision and high visual acuity. Cones tend to die in later-stage eye diseases. If rods can be regenerated from inside the eye, this might be a strategy for treating diseases of the eye that affect photoreceptors.”

Photoreceptors are light-sensitive cells in the retina, located in the back of the eye, that signal the brain when activated. In mammals, including mice and humans, photoreceptors fail to regenerate on their own. Like most neurons, once mature they no longer divide.

Scientists have long studied the regenerative potential of Müller glia because in other species, such as zebrafish, they divide in response to injury and can turn into photoreceptors and other retinal neurons. The zebrafish can thus regain vision after severe retinal injury. In the lab, however, scientists can coax mammalian Müller glia to behave more like they do in the fish. But it requires injuring the tissue.

“From a practical standpoint, if you’re trying to regenerate the retina to restore a person’s vision, it is counterproductive to injure it first to activate the Müller glia,” said Bo Chen, Ph.D. “We wanted to see if we could program Müller glia to become rod photoreceptors in a living mouse without having to injure its retina,” said Chen, the study’s lead investigator.

In phase one of a two-phase reprogramming process Chen’s team spurred Müller glia in normal mice to divide by injecting their eyes with a gene to turn on a protein called beta-catenin. A few weeks later, in phase two, they injected the mice’s eyes with factors that encouraged the newly divided cells to develop into rod photoreceptors.

The researchers found that the newly formed rod photoreceptors looked structurally no different from real photoreceptors.  Additionally, synaptic structures that allow the rods to communicate with other types of neurons within the retina had also formed. To determine whether the Müller glia-derived rod photoreceptors were functional, they tested the treatment in mice with congenital blindness, which meant that they were born without functional rod photoreceptors.

In the treated mice that were born blind, Müller glia-derived rods developed just as effectively as they had in normal mice. Functionally, they confirmed that the newly formed rods were communicating with other types of retinal neurons across synapses. Furthermore, light responses recorded from retinal ganglion cells — neurons that carry signals from photoreceptors to the brain — and measurements of brain activity confirmed that the newly-formed rods were in fact integrating in the visual pathway circuitry, from the retina to the primary visual cortex in the brain.

Chen’s lab is conducting behavioral studies to determine whether the mice have gained the ability to perform visual tasks such as a water maze task. Chen also plans to see if the technique works on cultured human retinal tissue.

This is a fascinating development and one that we will definitely be following.

To read the original article in its entirety, click here. https://www.sciencedaily.com/releases/2018/08/180815130544.htm