Is Poor Vision the Cause of Dementia???

Posted on October 4, 2024 by Dawn Kaplan

A new study out of John Hopkins Bloomberg School of Public Health found that improvements to what are considered common vision problems could possibly prevent dementia in as much as 20% of older people.

It’s important to note that the study doesn’t prove that having visual problems lead to or cause dementia. Rather the study confirms what earlier studies have suggested…that there is a link between these two conditions.

The study preformed a post-mortem investigation of 86 human donors who had been diagnosed with cognitive issues. The investigation revealed that changes to the retina corresponded to changes to the regions of the brain responsible for memory and time perception. In fact, it appears the some eye conditions are tied to specific types of dementia; age-related macular degeneration tends to occur in tandem with Alzheimer’s disease, while glaucoma seems to be more commonly tied to vascular dementia.

The study, which consisted of 2767 older patients, found that up to 19% of dementia cases had some form of vision problem, including loss of sensitivity in contrast and being able to distinguish small details (like text) called visual acuity. The link between dementia and vision was 9 times higher when contrast sensitivity was included instead of just visual acuity. Loss of sensitivity occurs with macular degeneration and cataracts.

Some factors were not included in the study: different races, impact of glasses or contacts, which will hopefully lead to additional studies and more answers.

This research was first published in JAMA Ophthamology.

Read the article in its entirety: www.sciencealert.com/your-eyesight-could-be-putting-you-at-risk-of-developing-alzheimers

Can cadavers help restore vision to the blind?

Posted on May 10, 2021 by Dawn Kaplan

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)

Eye infection in contact lens wearers due to poor hygiene can cause blindness

Posted on March 31, 2019 by Dawn Kaplan

There are reports of an outbreak of a rare but essentially preventable eye infection that can cause blindness, identified in contact lens wearers in a new study led by UCL and Moorfields Eye Hospital researchers. The research team found a threefold increase in Acanthamoeba keratitis since 2011 in South-East England.

The findings showed that reusable contact lens wearers with the eye infection were more likely to have used an ineffective contact lens solution, have contaminated their lenses with water or reported poor contact lens hygiene. “This infection is still quite rare, usually affecting 2.5 in 100,000 contact lens users per year in South East England, but it’s largely preventable. This increase in cases highlights the need for contact lens users to be aware of the risks,” said the study’s lead author, Professor John Dart (UCL Institute of Ophthalmology and Moorfields Eye Hospital NHS Foundation Trust).

Acanthamoeba keratitis is an eye disease that causes the front surface of the eye, the cornea, to become painful and inflamed, due to infection by Acanthamoeba, a cyst-forming microorganism.

The most severely affected patients (a quarter of the total) have less than 25% of vision or become blind following the disease and face prolonged treatment. Overall 25% of people affected require corneal transplants to treat the disease or restore vision.

Anyone can be infected, but research shows that contact lens users face the highest risk, due to a combination of increased exposure to infection, for reasons not fully established, as a result of contact lens wear and contamination of lens cases.

Alongside these findings, they conducted a case-control study of people who wear reusable contact lenses on a daily basis (although the disease is also associated with disposable lenses), comparing those who had a diagnosis of Acanthamoeba keratitis to those who had come in to Moorfields A&E for any other reason, from 2011 to 2014.

The case-control study included 63 people with Acanthamoeba keratitis and 213 without. They all completed a questionnaire, from which the researchers found that the risk of developing the disease was more than three times greater amongst people with poor contact lens hygiene, people who did not always wash and dry their hands before handling their lenses, those who used a lens disinfectant product containing Oxipol (now phased out by the manufacturer), and for people who wore their contacts while in swimming pools or hot tubs. Showering and face washing while wearing contact lenses are also likely to be risk factors.

Acanthamoeba is more commonly found in the UK than in other countries, likely due to higher levels found in domestic (as opposed to mains) water supplies, so that water contamination of contact lenses is of particular concern in the UK.

The researchers say the current outbreak is unlikely to be due to any one of the identified risk factors in isolation.

“People who wear reusable contact lenses need to make sure they thoroughly wash and dry their hands before handling contact lenses, and avoid wearing them while swimming, face washing or bathing. Daily disposable lenses, which eliminate the need for contact lens cases or solutions, may be safer and we are currently analysing our data to establish the risk factors for these,” said Professor Dart.

To read to original article in its entirety, click here. https://www.sciencedaily.com/releases/2018/09/180921082952.htm

Human retinas grown in a dish show how color vision develops

Posted on March 24, 2019 by Dawn Kaplan

Human retinas were grown from scratch by biologists at Johns Hopkins University to determine how cells that allow people to see color develop.

The research lays the foundation for researchers to develop therapies for eye diseases such as color blindness and macular degeneration.

“Everything we examine looks like a normal developing eye, just growing in a dish,” said Robert Johnston, a developmental biologist at Johns Hopkins. “You have a model system that you can manipulate without studying humans directly.”

Johnston’s lab explores what happens in the womb to turn a developing cell into a specific type of cell, an aspect of human biology that is largely unknown.

Johnston and his team focused on the cells that allow people to see blue, red and green — the three cone photoreceptors in the human eye.

Previously the majority of vision research has been on mice and fish, neither of these species has the dynamic daytime and color vision of humans. So Johnston’s team had to create the human eyes they needed — with stem cells.

“Trichromatic color vision delineates us from most other mammals,” said lead author Kiara Eldred, a Johns Hopkins graduate student. “Our research is really trying to figure out what pathways these cells take to give us that special color vision.”

Over several months, as the cells grew in the lab and became full-blown retinas, the team found the blue-detecting cells materialized first, followed by the red- and green-detecting ones. They found the key to the molecular switch was the ebb and flow of thyroid hormone. Important to note is the level of this hormone wasn’t controlled by the thyroid gland, which of course isn’t in the dish, but entirely by the eye itself.

“What’s exciting about this is our work establishes human organoids as a model system to study mechanisms of human development,” Johnston said. “What’s really pushing the limit here is that these organoids take nine months to develop just like a human baby. So what we’re really studying is fetal development.”

This groundbreaking work can lead to all sorts of applications is the vision deficiency arena.

To read the article in its entirety click here. https://www.sciencedaily.com/releases/2018/10/181011143112.htm

A common Diabetes medication may actually help prevent development of Macular Degeneration, a common cause of blindness

Posted on March 17, 2019 by Dawn Kaplan

According to an article published on October 29, 2018 by American Academy of Ophthalmology Researchers from Taiwan have shown that people with type-2 diabetes who were treated with Metformin showed a significantly lower rate of age-related macular degeneration (AMD).The study further suggests that the anti-inflammatory and anti-oxidative effects of metformin can protect against AMD while also controlling diabetes. The research was presented at AAO 2018, the 122nd Annual Meeting of the American Academy of Ophthalmology.

It has been long known that inflammation and oxidative stress play a key role in the development of both diabetes and AMD. Since metformin suppresses inflammation and oxidative stress, researchers in Taiwan theorized that it was possible that the diabetes drug could also protect against AMD, one of the leading causes of blindness in Americans over age 50, currently affecting about 2.1 million people in the United States alone.

The researchers used the Taiwan National Health Insurance Research Database, to collect data on all patients recently diagnosed with type 2 diabetes from January 2001 to December 2013, dividing them into two groups: Those who took metformin (45,524 patients) and those who did not (22,681 patients). After following both groups for 13 years, the researchers found that patients in the metformin group had a significantly lower risk of developing AMD. In fact, half as many patients in the metformin group had AMD compared to the control group.

“Our study is the first to reveal the protective effect of metformin on the development of AMD,” said lead investigator, Yu-Yen Chen, M.D. “While more study is required to determine just how metformin protects against the development of AMD, this is an exciting development for patients at risk.”

AMD is a degenerative disease that happens when part of the retina called the macula is damaged. It’s the part of the eye that delivers sharp, central vision needed to see objects straight ahead. Over time, the loss of central vision can interfere with everyday activities, such as the ability to drive, read, and see faces clearly.

Diabetes is a complex disease that can result from, genetics, environment, lifestyle factors, such as smoking and diet, and involve systemic diseases like heart disease. How the diabetes develops is not fully understood, but researchers have shown that oxidative stress and inflammation play a critical role in the development and progression of AMD. Drusen formation, the earliest clinical finding, has been shown to result from a localized inflammatory response.

The research on Metformin provides a hope that blindness need not be an eventuality for most people afflicted with diabetes.

Read Original Article: https://www.sciencedaily.com/releases/2018/10/181029102836.htm

Wearable Computer Gloves ‘Teach Braille’ Passively

Posted on September 29, 2014 by Dawn Kaplan

More than 39 million people around the world are blind. But for about 10% of these individuals, Braille – a reading and writing system that utilizes a series of raised dots that represent letters, numbers and punctuation – is a valuable tool. Braille is something lacking in most school systems, and is difficult to learn as we grow older when the majority of blindness occurs. So could this new wearable glove be the solution to teaching Braille to the larger vision –impaired population?

Researchers from the Georgia Institute of Technology have developed a wearable computer glove that can teach braille, even when the user’s attention is on another activity. The research team – including Thad Starner, a professor at Georgia Tech and a technical/lead manager on Google’s Project Glass – first created a technology-enhanced glove back in 2008, called Piano Touch. The glove could teach individuals how to play piano melodies in 45 minutes.

Their latest creation is an improvement on Piano Touch, which has been built around a process called passive haptic learning (PHL) – the idea that people can learn a skill unconsciously without devoting full attention to what they are learning.

For their study, participants were required to wear the gloves during a series of tasks. The gloves consist of small vibrating motors that are stitched into the knuckles.

Image credit: Georgia Tech.

In the first task, the motors in the glove vibrated in a sequence that mimicked a typing pattern of a premeditated phrase in Braille. The participants were given audio cues that let them know what Braille letters were produced through typing the sequence.

Each participant was then required to type the phrase once on a keyboard without any vibrations or audio cues while the researchers measured their accuracy.

In the next task, participants played a computer game for 30 minutes – as a distraction – while wearing the glove. Half of the participants were presented with repeated vibrations and audio cues that represented the same Braille phrase as the previous task, while the remaining participants acted as a control group and were only given audio cues.

The subjects had no previous knowledge of Braille and the tasks did not include visual feedback, meaning participants were unaware of their accuracy. On comparing the participants’ results with those of the first task, the team found that those in the control group had about the same level of accuracy.

However, those who had repeated vibrations and audio cues in the second task were 30% more accurate, with some even gaining 100% accuracy. Furthermore, the researchers found that these participants were then able to effectively go from writing Braille to reading it.

“After the typing test, passive learners were able to read and recognize more than 70% of the phrase’s letters,” says study co-author Caitlyn Seim, a student at Georgia Tech.

Seim is now in the process of conducting another study, which involves using the glove to teach the full Braille alphabet to participants. She says that so far, 75% of subjects have demonstrated perfect typing accuracy. In addition, participants were able to recognize and read more than 90% of Braille letters after 4 hours of learning.

To read the original article, please click here:

http://www.medicalnewstoday.com/articles/278719.php

Do Your Eye Movements Say You Are in Love or Lust?

Posted on September 22, 2014 by Dawn Kaplan

Eye Movements

Have you ever been on a date and wondered if the other person was romantically or sexually attracted to you? Well, wonder no more! Researchers studying eye patterns have found that where your date focuses their eyes on you could reveal whether he or she is romantically or sexually attracted.

Specifically, the findings reveal that eye patterns center on a stranger’s face if the viewer regards that person as a potential romantic love partner, whereas the viewer focuses more on the other person’s body when the feeling is one of sexual desire. Though this may seem like an obvious progression, researchers say that automatic judgment can happen as quickly as half a second, producing contrasting gaze patterns.

The research team, from the University of Chicago, has published their results in the journal Psychological Science.

For this study, researchers had male and female university students view a series of black-and-white photos of strangers. The participants examined photos of young, adult heterosexual couples who were interacting with each other. Then, in another part of the study, the participants looked at photos of attractive people of the opposite sex who were looking directly at the camera.

None of these photos contained nudity or erotic images, note the researchers.

For both parts of the study, the participants sat in front of a computer and were asked to decide as quickly as possible whether the people in the photos drew out feelings of sexual desire or romantic love.

The time it took for the subjects to identify romantic love versus sexual desire did not differ significantly, which the researchers say shows that the brain can quickly process both emotions.

However, after analyzing the eye-tracking data, the researchers found that people tended to fixate their eyes on the face when the image evoked a feeling of romantic love, whereas when the images elicited sexual desire, the viewers’ eyes moved from the face to focus on the rest of the body.

And this result was the same for both male and female participants.

So, if you are wondering what someone’s thoughts are about you upon first meeting you…check out their eye movement!

To read the original article, please click here:

http://www.medicalnewstoday.com/articles/279860.php

Vision-Correcting Displays Makes Reading Glasses Like So Yesterday!

Posted on September 15, 2014 by Dawn Kaplan

What if computer screens corrected to your specific vision? It may happen sooner than you think!

The researchers at University California -Berkley are developing computer algorithms that compensate for an individual’s visual impairment, creating vision-correcting displays that enable users to see text and images clearly without wearing eyeglasses or contact lenses. This technology could potentially help hundreds of millions of people who currently need corrective lenses to use their smart phones, tablets and computers. One group who would benefit greatly, for example, are those afflicted with presbyopia, a type of farsightedness in which the ability to focus on nearby objects is gradually diminished as the aging eyes’ lenses lose elasticity. You all know who I am talking about…. The people with the Walgreen’s reading glasses that they need to read a text, a phone number, an email, etc.

Perhaps more importantly, the displays could one day aid people with more complex visual problems, known as high order aberrations, which cannot be corrected by eyeglasses, said Brian Barsky, UC Berkeley professor of computer science and vision science, and affiliate professor of optometry.

“We now live in a world where displays are ubiquitous, and being able to interact with displays is taken for granted,” said Barsky, who is leading this project. “People with higher order aberrations often have irregularities in the shape of the cornea, and this irregular shape makes it very difficult to have a contact lens that will fit. In some cases, this can be a barrier to holding certain jobs because many workers need to look at a screen as part of their work. This research could transform their lives, and I am passionate about that potential.”

This latest approach improves upon earlier versions of vision-correcting displays that resulted in low-contrast images. The new display combines light field display optics with novel algorithms.

Huang, now a software engineer at Microsoft Corp. in Seattle, noted that the research prototype could easily be developed into a thin screen protector, and that continued improvements in eye-tracking technology would make it easier for the displays to adapt to the position of the user’s head position.

“In the future, we also hope to extend this application to multi-way correction on a shared display, so users with different visual problems can view the same screen and see a sharp image,” said Huang.

As more and more applications are being found for IPAD’s and Smart Phones are becoming much more common place, this is indeed a timely advancement.

The National Science Foundation helped support this work.

Video: http://www.youtube.com/watch?v=6V2x3nLQdA0

To read the original article, please click here: http://www.sciencedaily.com/releases/2014/07/140729152921.htm

Age-related macular degeneration can occur much earlier than originally thought

Posted on September 8, 2014 by Dawn Kaplan

Age-related macular degeneration (AMD) is the most common cause of visual impairment and blindness in industrialized countries. But the question is whether it can be defined as a disease in people 50 or older. In a recent study to determine the incidence of age-related macular degeneration undertaken as part of the Gutenberg Health Study of the University Medical Center of Johannes Gutenberg University Mainz (JGU) results showed that even persons under the age of 50 may be affected by an early form of the eye disease. Just under 4 percent of the 35 to 44-year-old subjects in the population-based study were found to be suffering from AMD.

National Eye Institute of the NIH

In order to identify the age- and gender-specific incidence of AMD, the research team assessed the status of the ocular fundus of 4,340 participants in the Gutenberg Health Study. Evaluated were vascular structure, the head of the optic nerve, and the macula of the eye, which is the point of sharpest vision. The results, not surprisingly, documented that the incidence of AMD increases with age. What was surprising, was the fact that even persons under the age of 50 can already be affected by early stage AMD. In the age group of 35- to 44-year-olds, 3.8 percent of the subjects in the Study were found to be suffering from the disease. The findings thus contradict the accepted assumption that age-related macular degeneration only occurs in the section of the population that is over 50 years old.

Age-related macular degeneration leads to loss of visual acuity. The cause is damage to the cells in the region of the central retina also known as the “yellow spot.” Information on the annual number of individuals who develop AMD is still insufficient, but the Mainz-based researchers hope to remedy this situation with their next project. As the Gutenberg cohort was subjected to a follow-up examination five years after inclusion in the study, the research group now has access to more relevant and reliable data. “The prospective design of the study, in combination with the availability of interdisciplinary research data, should make it possible for us to identify risk factors for the development of late forms of AMD in our cohort. We are looking forward with some excitement to the results,” explained the team.

With more on-going research projects like these we continue to learn more about the diseases that can affect our eyes and vision and in turn how we can treat and hopefully cure them.

Read the original article at https://www.sciencedaily.com/releases/2014/07/140721100125.htm

Human Eye Movements for Vision Are Remarkably Adaptable

Posted on November 16, 2013 by Dawn Kaplan

Our eyes are constantly on the move, darting this way and that four to five times per second. Our eyes have the ability to change direction and focus at an incredible speed.

A new study published in the Cell Press journal Current Biology on August 15, states that researchers have found that the precise manner of those eye movements can change within a matter of hours. This discovery might lead to a way to help those with macular degeneration better cope with vision loss.

“The system that controls how the eyes move is far more malleable than the literature has suggested,” says Bosco Tjan of the University of Southern California. “We showed that people with normal vision can quickly adjust to a temporary occlusion of their foveal vision by adapting a consistent point in their peripheral vision as their new point of gaze.”

The fovea is the small, center-most portion of the retina, which is responsible for our Eye Chart high-resolution vision. In other words, it is the “pointer” we use to direct our eyes to different parts of a scene, building an image of our world. For those with age-related macular degeneration, increasing loss of foveal vision leads to visual impairment and blindness.

The researchers simulated a loss of foveal vision in six normally sighted young adults by blocking part of a visual scene with a gray disc that followed the individuals’ eye gaze. Once the disc was in place, the individuals were asked to complete demanding object-following and visual-search tasks. The researchers found that within three hours of working on those tasks, all six participants showed a remarkably fast and spontaneous adjustment of eye movements. Once the visual adjustment had been made by the participants, the change in their “point of gaze” was retained for a period of weeks and was reengaged whenever their foveal vision was blocked.

Tjan and the other two researchers stated they were surprised by the rate of this adjustment. They note that patients with macular degeneration frequently do adapt their point of gaze, but in a process that takes months, not days or hours. They suggest that practice with a visible gray disc like the one used in the study might help speed that process of visual rehabilitation along. The discovery also reveals that the oculomotor (eye movement) system prefers control simplicity over optimality. Tjan states “Gaze control by the oculomotor system, although highly automatic, is malleable in the same sense that motor control of the limbs is malleable.”

The result of this study is potentially very good news for people who experience loss of their foveal vision due to macular diseases. This study shows that it may be possible to create the right conditions for the oculomotor system to quickly adjust.

To read the original article, visit: https://www.sciencedaily.com/releases/2013/08/130815133447.htm