New Study Finds Test of Protein Levels in the Eye a Potential Predictor of (Future) Alzheimer’s Disease

Low levels of amyloid-β and tau proteins, biomarkers of Alzheimer’s disease (AD), in eye fluid were significantly associated with low cognitive scores, according to a new study published in the Journal of Alzheimer’s Disease. Led by researchers at Boston Medical Center, the study is the first to connect these known AD protein biomarkers in the eye to mental status. These findings indicate that proteins in the eye may be a potential source for an accessible, cost-effective test to predict future Alzheimer’s disease.

Diagnosing and starting treatment for AD before symptoms begin is key to managing the disease, because by the time symptoms appear it is often too late for current treatments to have any meaningful effect. Abnormal amounts of amyloid- β and tau proteins are biomarkers of AD, and deposits of amyloid proteins in the brain begin many years prior to symptoms of the disease. Previous research has shown an association between low levels of amyloid-β and tau proteins found in the cerebrospinal fluid obtained by lumbar puncture tests and preclinical AD, when pathological changes of AD present in the brain, but before the onset of clinical symptoms. However, lumbar puncture tests are expensive and inconvenient for many patients to undergo.

In this study, researchers used samples of eye fluid from 80 patients who were previously scheduled for eye surgery. The fluid extracted during these surgeries is typically discarded. Researchers tested the eye fluid to determine the levels of amyloid-β and tau proteins, and correlated those levels to the results of a baseline cognitive test. Low levels of these biomarker proteins were significantly associated with lower cognitive scores among the patients.

“These findings could help us build an accessible, and minimally invasive test to determine Alzheimer’s disease risk, especially among patients with eye disease,” says Lauren Wright, MD, first author on the study and ophthalmology fellow at BMC. “We noted that some of the participants who had low levels of protein biomarkers in their eye fluid already had signs of mild to moderate dementia based on their cognitive scores.”

These results reaffirm previous studies suggesting that patients with eye disease are at-risk for the development of AD, and suggest that further investigation in patients with eye disease may yield results that could be generalizable to larger populations.

“This is a great step in discovering the eye’s potential role in diagnosing preclinical Alzheimer’s disease, and further study is needed comparing protein biomarkers in the eye with more in-depth neurological testing,” adds Manju Subramanian, MD, senior author, principal investigator, and ophthalmologist at BMC.

Source: Boston Medical Center


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Eating Colourful Fruits and Vegetables Lowering Risk of Age-related Cataracts

A $5.7 billion global medical bill to restore sight for the estimated 45 million people with cataracts could be slashed in half by a diet rich in colourful fruits and vegetables, according to an international study.

Researchers from China and the University of South Australia have published the first study of its kind to verify the link between foods high in antioxidants and a lower risk of age-related cataracts (ARC).

UniSA Senior Research Fellow Dr Ming Li and colleagues from Xi’an Jiaotong University analysed 20 studies from around the world looking at the impact of vitamins and carotenoids on cataract risk.

Despite some inconsistencies, the findings overwhelmingly support the benefits of eating citrus fruits, capsicum, carrots, tomatoes and dark green vegetables such as spinach, broccoli and kale to delay the onset of ARC.

Their paper has been published in the American Journal of Clinical Nutrition ahead of World Optometry Week (March 26-30).

“Age-related cataracts are the leading cause of visual impairment among the elderly throughout the world, with unoperated cataracts contributing to 35 per cent of all blindness,” Dr Li says. “Although cataract extraction surgery is an effective method to restore vision, it will have cost society more than $5.7 billion by 2020.”

With the population ageing dramatically and an increasing number of people needing surgery, urgent action is needed, the researchers say.

“If we could delay the onset of ARC by 10 years it could halve the number of people requiring surgery.”

Improvements would rely on global changes to most of the world’s diet, however, with current consumption of antioxidants well below the recommended level to prevent age-related cataracts.

Source: University of South Australia


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Eye-Soothing Tips for Computer Users

Screens: They’re at work, at home and even in the palm of your hand. But stare too long at them and your eyes — and mind — could pay a price, experts warn.

For example, too much screen time can lead to problems such as eye strain, dry eye, headaches and insomnia, the American Academy of Ophthalmology warns.

“Eyestrain can be frustrating. But it usually isn’t serious and goes away once you rest your eyes or take other steps to reduce your eye discomfort,” said Dr. Dianna Seldomridge, clinical spokesperson for the academy.

The average office worker spends 1,700 hours a year in front of a computer screen, according to a recent study. That doesn’t include time spent using smart phones and other digital devices.

Here, the academy offers tips for preventing eye problems:

  • Keep the screen at arm’s length, about 25 inches away (eyes have to work harder to see close up) and position the screen so that your gaze is slightly downward.
  • Use a matte screen filter to reduce glare that can aggravate your eyes. Be aware that if a screen is much brighter than the surrounding light, your eyes have to work harder to see. Adjust your room lighting and try increasing the contrast on your screen.
  • Remember to blink and follow the 20-20-20 rule. Take a break every 20 minutes by looking at an object 20 feet away for 20 seconds. This will help your eyes relax.
  • Lubricate your eyes with artificial tears when they feel dry. In offices with dry air, desktop humidifiers can be beneficial.

“If these tips don’t work for you, you may have an underlying eye problem, such as eye muscle imbalance or uncorrected vision, which can cause or worsen computer eyestrain,” Seldomridge said in an academy news release.

Source: HealthDay

Muted Rainbow – Color-blind Persons Can’t See the Full Range of Colours

When Paul Cprek was interviewing for jobs, he sometimes video chatted with his mother or sister beforehand for advice. He wasn’t concerned about what to say in interviews. He was worried about what to wear. Cprek is color-blind, and picking out a shirt and tie to match can be tricky. “[Job interviews are] all about first impressions, so I was curious, did I get it right?” says Cprek, 29, an investment consultant in New York City.

Color Uncoordinated

Color blindness describes various forms of an inherited trait that scientists call color vision deficiency, says Jay Neitz, PhD, professor of ophthalmology at the University of Washington in Seattle. Cprek has the most common type, red-green color deficiency, which affects about one in 12 men and one in 200 women of Northern European ancestry, according to the National Institutes of Health’s National Eye Institute in Bethesda, MD. Dark green and red look the same to him and are hard to distinguish from brown. He also has trouble distinguishing dark blue from purple.

Cprek was in elementary school when he first realized that he was color-blind like his paternal grandfather. “I was in art class and getting things wrong,” he recalls. Not seeing the range of colors that most people do still trips him up at times, but “it’s not a big obstacle for me in my daily life,” he says.

Color blindness is shorthand for a more complex process involving the eyes and brain, says Bart Leroy, MD, PhD, director of the ophthalmic genetics and retinal degeneration clinics at the Children’s Hospital of Philadelphia.

The retina uses two types of cells: rods, which are responsible for night vision, and cones, which are responsible for daytime vision, including color vision, he explains. The cones are divided into three types that absorb different wavelengths of light: red, green, and blue. Depending on what type of color vision deficiency a person has, cone cells are either missing or not sufficiently sensitive; the result is that only certain color information is being recognized and sent to the brain, says Dr. Leroy. A person with red-green deficiency doesn’t see those colors as most people do and may also have difficulty distinguishing between certain shades of blue and purple, which is comprised of red and blue.

A Genetic Link

While people with normal color vision can’t imagine not seeing all their favorite colors—think of a box of crayons with colors missing—people with color vision deficiency only know their environment as they perceive it. “People don’t know what they don’t see,” says Dr. Leroy.

Color vision deficiency is X-linked, meaning genetic mutations associated with the condition are passed along on the X chromosome, says Dr. Leroy. The condition is more likely to affect males, who have an X and a Y chromosome. Females have two X chromosomes, which allows any genetic mutations related to color blindness on one X chromosome to be overridden by normal genes on the other.

Children should be routinely tested for color vision, says Dr. Leroy. If they are color-blind, they and their parents and teachers can come up with strategies for dealing with activities where distinguishing color differences might be a problem.

Screening For The Condition

Karen Rae Levine learned her younger son was color-blind when his preschool teacher said he was having trouble with blue and purple patterns. She took him to an optometrist, who confirmed his color blindness and told her, “There’s nothing you can do, so don’t worry about it.”

Levine didn’t quite agree with that laid-back sentiment. She immersed herself in research and became an activist, pushing for color vision screening at her son’s school and elsewhere in the New York district where they lived at the time. “Color blindness often isn’t understood or even recognized, especially by the educational system,” says Levine, who now lives in Huntington, NY. “Teachers were shocked to learn that they probably had a color-blind child in every class.”

It’s important for teachers to know that color blindness is fairly common, says Levine. Otherwise, they may think a child isn’t following directions or doesn’t understand a lesson. In kindergarten, for example, everything is color-coded, she says. “The teacher says, ‘You sit at the red table. You sit on the orange square.’”

Her experiences as a mom with a color-blind son—including receiving a green Valentine’s Day card—led her to self-publish a children’s book, All About Color Blindness: A Guide to Color Vision Deficiency for Kids (and Grown-Ups Too), in 2013. She says kids may be reluctant to admit that they perceive colors differently than their friends, but she wants them to be confident in their abilities and speak up when they need to: “I am color-blind. Can you help me pick out a marker to make a rainbow?”

An Evolving Trait

The ability to see in three colors, or trichromatic vision, is a trait that evolved in higher-order primates, including humans, as they relied more on visual cues than on their sense of smell for survival, says James Lupski, MD, PhD, professor of molecular and human genetics at Baylor College of Medicine in Houston. Dr. Lupski has been involved in mapping the human genome and is interested in rearrangements of genetic coding that result in traits such as color blindness.

“Color blindness is a benign trait that doesn’t compromise your life too much,” he says. People can generally drive, for instance, because they know that red is at the top of a stoplight and green is at the bottom and can recognize when the light changes.

Before the 1980s, the “biological basis of color blindness was not understood at all,” says Dr. Neitz, who runs a research lab focused on color blindness with his wife, Maureen Neitz, PhD. The couple is developing gene therapy and genetic testing for color blindness.

Monkeying Around With Color

Dr. Neitz says he gets a lot of emails from people with color blindness. Men have confided, for example, that they can’t relate to their wife’s enthusiasm for a fall foliage tour or a sunset stroll. A friend with red-green color blindness told him he has trouble seeing when the key card to unlock a hotel room door signals the change from red to green. Other, more substantive concerns include not being able to pursue a color-dependent career such as airline pilot, police officer, or chemist, or getting in a car crash because a red light doesn’t register.

In a 2009 study published in Nature, the Neitzes’ team reported findings from a gene therapy study to address color vision deficiency in squirrel monkeys with red-green color blindness. The scientists injected a viral vector carrying a color pigment gene underneath the retina to replace the missing pigment. Dr. Neitz says there was some skepticism about whether it would work because the monkeys’ brains were already accustomed to processing a limited spectrum of colors. “Color vision is all about how the information that comes from the three different kinds of cones in the eye is processed by the brain,” he says.

But the monkey experiment suggests that the brain can adapt to new color information. Dr. Neitz says tests to evaluate the monkeys’ responses to color cues following gene therapy indicated that they could see a full range of colors. The goal is to test the approach in humans at some point, but color vision deficiency isn’t a high priority. “Obviously, there are far worse conditions we should be working on first,” Dr. Leroy says.

Basic Hues

Cprek works around his color blindness. If he plays a sports video game with a friend, he asks him to select team jerseys with the most contrast, usually white and a dark color. At work, he creates graphs and pie charts that provide contrast to his eyes. Highlighting in a document occasionally stumps him, but he asks his colleagues to double-check things if he isn’t certain.

Cprek says that while he asks for fashion advice for special events, he has learned that keeping things simple is the best way to go, especially off the job. “I try to stick with blue jeans and a white T-shirt instead of getting too creative with colors.”

Source: Brain & Life

Protect Your Aging Eyes From Macular Degeneration

Age-related macular degeneration (AMD) is an incurable eye disease that affects millions of older Americans, but there are a number of things you can do to reduce your risk, a vision expert says.

AMD causes blurred central vision due to damage to the macula, a small area at the back of the eye, and it is most common after age 60, according to the U.S. National Eye Institute.

AMD is also more common in women and whites, and at-risk patients should get regular eye exams, advised Dr. Julie Rosenthal, a retina specialist at the University of Michigan’s Kellogg Eye Center.

She said there are a number of things people can do to help slow or possibly prevent AMD. If you smoke, try to quit. Smoking may double the risk of AMD.

Find out if you have a family history of the disease. People with a first-degree relative with AMD have a much greater risk of developing it. If you have a family history of the disease, watch for potential symptoms such as difficulty recognizing faces, struggling to adapt to low light and seeing straight lines that appear wavy.

Eat lots of spinach, kale, Swiss chard and other leafy greens, which are high in antioxidant vitamins that help protect against cellular damage from free radicals, which can contribute to eye disease, according to Rosenthal.

If you have a poor diet, consider taking multivitamins. People at risk of advanced AMD should ask their doctor about a specialized blend of supplements called AREDS. This is “not a treatment or cure but can decrease your risk of getting the more severe forms of AMD,” Rosenthal said in a university news release.

When outside, wear sunglasses that provide protection from UV and blue light that can cause retinal damage. Sunglasses with a “UV 400” label are recommended by the American Macular Degeneration Foundation.

Maintain healthy blood pressure and weight. Poor blood circulation due to high blood pressure can restrict blood flow to the eyes, thus contributing to AMD. Losing weight is a proven way to lower blood pressure.

Use a tool called an Amsler grid to check for vision problems related to macular damage. When staring at the grid, if you notice that the central part of your vision in one eye has become darker or the grid lines are wavy, call your doctor, Rosenthal said. Keep the grid in a place that reminds you to use it daily.

Source: HealthDay