Women’s Eye Health

With this being Women’s History Month, we thought it appropriate to discuss women’s eye heath. Your vision is one of the most important things in your life. Vision loss can make everyday tasks more difficult, impede your work and lead to depression.

According to Prevent Blindness America (PBA), 66% of people who are blind or visually impaired are women. This is primarily due to the fact that women have more risk factors for vision loss than men. Sadly the same study also revealed that only 9% of women realize this. Early intervention can help prevent blindness in many cases. Many blinding eye diseases can be treated to prevent blindness and almost all eye injuries can be prevented.

Here is a closer look at why women are affected more than men, and what condition they need to be aware of for early diagnosis and sight-saving treatments.

Why Women Lose Vision

They live longer than men and many eye diseases are age-related. Examples are cataracts, macular degeneration and diabetic retinopathy. The rates of these diseases are increasing as the baby boomer population ages.

Some eye diseases are intrinsically more prevalent among women, like dry eye syndrome which is believed to be linked to hormones. It is 2-3 times more likely in women than men. Hormonal changes can influence vision changes across the life span of a woman, from pregnancy to post-menopause.

Women have higher rates of autoimmune diseases such as lupus, rheumatoid arthritis and multiple sclerosis. The serious side effects of these conditions can affect your eyes, causing vision loss.

Social and economic factors can access to health care for women restricting early detection and treatment which could prevent or limit vision loss.

While behavioral and environmental factors are not restricted to women, poor nutrition and obesity can cause diabetes and subsequent diabetic retinopathy; while smoking is also a proven risk factor for eye diseases such as cataracts and macular degeneration. Women under 23 are the fastest growing segment of new smokers.

Eye Conditions More Prevalent in Women

Cataracts are the world’s leading cause of blindness. They are the result of a clouding of your eye’s normally clear lens. They can be treated with cataract surgery, where the cloudy lens is replaced with a clear synthetic lens.

Glaucoma is the second-leading cause of blindness in the Us. It is called the silent thief of sight because there is no warning. It happens when pressure in the eye — intraocular pressure or IOP — is too high, damaging the optic nerve which sends vision signals to the brain. Open-angle glaucoma, the most common type, affects men and women equally. But women are 2-4 times more likely than men to get closed-angle glaucoma. One of the possible reasons for this is that the front chamber between the iris and cornea is shallower in women than men and can block fluids from draining out of the eye, thus increasing pressure. Glaucoma is also genetic, meaning you are at higher risk if someone in your family has had glaucoma. When caught early, there are treatments that can help control your IOP. If it is not controlled early, blindness can result and it is irreversible.

Age-related macular degeneration (AMD) is the number one cause of vision loss in people over 40 in the US. One of the reasons women are at higher risk is because they tend to live 5-7 years longer than men. AMD gradually destroys the central part of your sight that helps you read or drive. There are two types of AMD. Dry AMD, which occurs when drusen accumulate under the retina. There is no treatment for dry, yet accounts for 90% of the cases. Wet AMD occurs when new blood vessels grow and leak between the retina and eye’s outer layer. There is a treatment of anti-VEGF injections for this version of AMD. The earlier the disease is diagnosed and treated, the better the results. Like glaucoma, it is an inherited eye disease.

Diabetic retinopathy is a result of diabetes. When blood sugar levels are too high, the vessels that feed the retina weaken and eventually leak, which cause the macula to swell. In its most dangerous form the retina may detach from the back of the eye leading to blindness. Diabetes is also hereditary, but controllable with early diagnosis and treatment.

Dry eye syndrome occurs when your eyes produce too few tears. Your eyes may burn, sting or feel gritty, making your vision blurry or you may blink more. Contrary to the name, you may appear weepy as the dryness may stimulates more tear production. Thanks to hormones, women are more susceptible. In postmenopausal women, the shift in balance between estrogen and progesterone can be responsible.

Pregnancy-related eye changes, like menopause, are caused by hormone shifts and can cause several temporary eye conditions, such as dry eye and corneal swelling.

3/10/16

Susan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

The Brain and the Eye – How They Work Together

The Brain and the Eye

The eye works like a camera. The iris and the pupil control how much light to let into the back of the eye, much like the shutter of a camera. When it is very dark, our pupils get bigger, letting in more light; when it is very bright our irises constrict, letting in very little light.

The lens of the eye, like the lens of a camera, helps us to focus. But just as a camera uses mirrors and other mechanical devices to focus, we rely on eyeglasses and contact lenses to help us to see more clearly.

The focus light rays are then directed to the back of the eye, on to the retina, which acts like the film in a camera. The cells in the retina absorb and convert the light to electrochemical impulses which are transferred along the optic nerve to the brain. The brain is instrumental in helping us see as it translates the image into something we can understand.

The eye may be small, but it is one of the most amazing parts of your body. To better understand it, it helps to understand the different parts and what they do.

Choroid
A layer with blood vessels that lines the back of the eye and is between the retina (the inner light-sensitive layer that acts like film) and the sclera (the outer white part of the eyeball).

Ciliary Body
The muscle structure behind the iris, which focuses the lens.

Cornea
The very front of the eye that is clear to help focus light into the eye. Corrective laser surgery reshapes the cornea, changing the focus to increase sharpness and/or clarity.

Fovea
The center of the macula which provides the sharp vision.

Iris
The colored part of the eye used to regulate the amount of light entering the eye. Lens focuses light rays onto the retina at the back of the eye. The lens is transparent, and can deteriorate as we age, resulting in the need for reading glasses. Intraocular lenses are used to replace lenses clouded by cataracts.

Macula
The area in the center of retina that contains special light-sensitive cells, allowing us to see fine details clearly in the center of our visual field. The deterioration of the macula can be common as we age, resulting in age related macular degeneration.

Optic Nerve
A bundle of more than a million nerve fibers carrying visual messages from the retina to the brain. Your brain actually controls what you see, since it combines images. Also the images focused on the retina are upside down, so the brain turns images right side up. This reversal of the images Is a lot like what a mirror does in a camera. Glaucoma can result when increase pressure in the eye restricts the flow of impulses to the brain, causing optic nerve damage and makes it difficult to see.

Pupil
The dark center opening in the middle of the iris changes size to adjust for the amount of light available to focus on the retina.

Retina
The nerve layer lining the back of the eye that senses light and creates electrical impulses that are sent through the optic nerve to the brain.

Sclera
The white outer coating of the eyeball.

Vitreous Humor
The clear, gelatinous substance filling the central cavity of the eye.

3/3/16

Susan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

4 Super Greens for Better Sight

A healthy diet not only helps your heart, but also your eyes. Your diet should include lots of fruits and vegetables to provide you with a natural source of nutrients to help protect your sight. As wonderful as supplements are, eating the actual foods is always better. Some of the best vegetables for you are the dark, leafy greens that are rich in valuable vitamins and nutrients. These are the super greens for better sight.

With the US experiencing bitter, freezing temperatures on the East Coast, while the West Coast is having summer in February, with record-breaking hot temperatures, I thought it would be interesting to see how you could enjoy those super greens, no matter what the temperature is outside. Below is a quick look at four dark leafy greens that are a great addition to a healthy diet, watercress, arugula, spinach and kale. For each vegetable I have included a recipe that is served hot, along with one that is served cold.

Here is what you need to know about super greens for better sight.

WATERCRESS

Watercress is a cruciferous plant and part of the brassica family, like arugula and kale. It contains vitamins A, B6, B12, C, K, iron, magnesium, calcium, phosphorus, lutein and zeaxanthin. In fact, weight for weight, watercress contains more vitamin C than an orange, more calcium than milk, more iron than spinach and more folate than bananas. Watercress has the highest amount of nutrients for the smallest amount of calories.

The health benefits of watercress include boosting immunity, cancer & diabetes prevention, reducing cognitive decline, thyroid support, better cardiovascular health and stronger bones. As for your eyesight, it can help prevent or slow the onset of age-related macular degeneration and possibly cataracts.

Watercress is most commonly enjoyed fresh in salads, but can also be use in pastas, casseroles, soups and sauces. Choose watercress with deep green, crisp leaves, with no signs of wilting. Trim the stems, rinse the greens in cold water and dry. It is best if used immediately, but can be store for up to four days in the refrigerator.

Watercress Soup by William Anatooskin

Watercress and Grapefruit Salad by Martha Stewart

ARUGULA

Arugula is also known as a salad or garden rocket. It is a small low growing herb that is packed with vitamins, minerals and antioxidants. It is rich in folates, vitamin A, B-complex, C and K and has copper, iron, calcium, potassium, manganese and phosphorus.

The health benefits of arugula include a lowered risk of cancer, healthy bones, strengthened brain function, improved mineral absorption and it boosts the immune system. Because of being a source of carotenoids, it also helps to slow the progression of age-related macular degeneration.

Arugula is popular in salads, used with milder greens to add a peppery flavor. But it can also be used in pastas, casseroles, pizzas, soups and sauces. Choose arugula that is crisp with green young leaves. Avoid the flowered harvest as those leaves are tough and have a bitter taste. Wash leaves in a bowl of water, swishing thoroughly to get rid of all sand and soil. Drain and pat dry before storing in the vegetable bin of your refrigerator for no more than a few days.

Grilled Stuffed Swordfish by Stormy Scarlett

Pasta Salad with Goat Cheese and Arugula by Martha Stewart

SPINACH

Spinach is a very popular leafy green vegetable, with two common varieties cultivated for food; the savory-type with dark green crinkled leaves and the flat-leaf type with smooth surfaced leaves. Spinach contains vitamin A, B-complex, C and K, along with lutein, zeaxanthin beta-carotene, potassium manganese, magnesium, copper and zinc.

The nutrients in spinach help improve blood glucose control in diabetes, lower the risk of certain cancers, reduce blood pressure, increase bone health and help iron deficiency. The lutein, zeaxanthin and beta-carotene help to potentially prevent and slow the progression of age-related macular degeneration. Lutein also works to protect the eye from free radical damage by helping filter out damaging blue and ultraviolet light.

Spinach is a universally popular vegetable, used around the world in a variety of ways, including salads, soups, noodles, pies, casseroles, dips, sauces, etc. Look for leaves that are dark green in color, crisp and not dull or yellow and spotted. Wash thoroughly to remove sand and soil, dry, trim away tough stems and store in the refrigerator for up to a week.

Turkey-Spinach Meatballs from Bon Appètit

Spinach Salad with Dates from Bon Appètit

KALE

Kale is a member of the mustard and cabbage families and has more nutrients than spinach. Less than ½ cup has 333% of the recommended daily allowance (RDA) of vitamin A, 587% RDA of vitamin K and 200% RDA of vitamin C. This frilly-leafed vegetable also has vitamin B-complex, lutein, zeaxanthin, beta-carotene, copper, calcium, sodium, potassium, iron, manganese, and phosphorus.

The health benefits of kale include healthy muscles and skin, improved blood glucose control, lower colon and prostate cancer risk, better cardiovascular health, stronger bone health, reduced neuronal brain damage and support for red blood cell formation. The advantage for your eyes comes from the lutein, zeaxanthin, beta-carotene and vitamin A, all which work to support a healthy retina. They help protect against blue and ultraviolet light as well as the early onset and progression of age-related macular degeneration. Because of the positive impact on diabetes it also reduces the onset and progression of diabetic retinopathy.

Kale is very versatile and can be served in a variety of ways including salads, soups and casseroles. It can also be braised, broiled, sautéed and even made into kale chips by tossing them in extra-virgin olive oil and sprinkled with your choice of cumin, curry powder, chili powder, red pepper flakes or garlic powder and baking at 275 degrees for 15-30 minutes depending on how crisp you want them to be. When shopping for kale look for leaves that are crispy and crunchy with a brilliant dark blue-green color. Wash thoroughly to remove soil and sand, dry well, and remove all tough stems. It is extremely perishable, so use it as quickly as possible.

Kale and Chicken Casserole by Martha Stewart

Kale with Pomegranate Dressing and Ricotta Salata from Bon Appètit

All of these dark green leafy vegetables are not only healthy for you, but can be used in many ways to make it easy to incorporate them into your diet. Here are a few ideas:

Throw a small handful into your blender when making your favorite smoothie
Add them to your next omelet or egg scramble
Use them for making pesto or adding to pasta sauce
Sauté with a small amount of extra-virgin olive and season with freshly ground black pepper and freshly grated Parmesan cheese to serve at a topping for your baked potato
Add it to your wrap, sandwich or flatbread

2/17/16

Susan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

Layers of the Retina

The retina at the back of the eye is essential for all vision. Each layer of cells in this tissue serves a specific purpose. As we prepare for Age-Related Macular Degeneration Awareness Month in February, a closer look at the layers of the retina and their function.

Layers of the Retina

Choroid – This is made up of a layer of blood vessels that supply oxygen and nutrients to the retina. Defect in the CHM gene can cause choroideremia, leaky blood vessels can expand in the retina causing wet age-related macular degeneration (AMD) and diabetic retinopathy.

Retinal pigment epithelium – This is a single layer of cells that provide essential nutrition and waste removal for the photoreceptor cells. Accumulation of waste can lead to AMD and Stargardt disease.

Photorecptors – This is where the rods and cones are located that convert light into electrical signals. Rods help you with night and peripheral vision. Cones are more concentrated in the macula (the central part of the retina) and proved central and color vision. Death of the rods can cause vision loss called retinitis pigmentosa, while AMD is the loss of central vision.

Horizontal cells – These cells are connect to the photoreceptors that surround the bipolar connected photoreceptor cells and help the help integrate and regulate the input from multiple photoreceptor cells, increasing your visual acuity.

Bipolar cells – The dependence of each layer of the retina on each other is exemplified here. These cells take the electrical information from the photoreceptor cells and pass it along to other retinal cells.

Ganglion cells – These cells extend to form an optic nerve that conveys information to the brain and take the electrical information from the bipolar cells and process it to determine shapes, contrast and color. Glaucoma vision loss results from high intraocular pressure that affects the optic nerve, interrupting the signals to the brain.

5 Elements of Accessible Web Design

A common misconception is that all you need to have a successful blog or website is good content. While content people want to read is important, if you can’t see it, or it is difficult to read, very few people are going to take the time to try. There is lots of good content to choose from.

Making your content easy to scan and read and using great graphics that can tell a story are just as important. Especially if you want to reach the millions of potential readers that are blind or visually impaired.

While a person with low vision (due to age-related macular degeneration, cataracts,glaucoma or other eye diseases that are related to aging) can increase font size or graphics by enlarging them with a pinch of the fingers or scroll of the mouse, the result is often blurry and still difficult to see.

If a person is blind and using a screen reader, what they hear may not match what is written or displayed. A picture without underlying descriptive text is worthless. And when a blind person is using a screen reader to read a web site, they will often tab from link to link to scan your article, skipping over your text, to get a sense of what the options are. “Click here” says doesn’t tell the reader anything.

Here are 5 essential elements of accessible web design.

12/15/15

Susan DeRenmer, CFRE
Vice President of Development
Discovery Eye Foundation

Low Vision Aging Adults at Higher Risk for Falls

Low vision in aging adults varies as do the occupational therapy techniques that might help older adults in becoming more independent. Mr. P has glaucoma resulting in a narrowed field of view. He is light sensitive, and keeps his blinds closed, darkening the house. He is responsible for doing his laundry, yet his washer and dryer are in the basement, causing a safety concern. Mrs. K has macular degeneration with 20/400 visual acuity. She has severely reduced contrast sensitivity, and can no longer drive or recognize faces easily. She no longer gets to the senior center for regular exercise sessions, which is concerning to her and her OT. Ms. T was diagnosed with diabetic retinopathy. She has struggled for years to accurately see her glucometer and insulin. She has recently developed peripheral neuropathy, leading to wheelchair dependency. Each of these patients is likely to leave their home less often because of their low vision, eventually leading to a decline in lower extremity weakness, balance, endurance and confidence. The fear of falling leads to more isolation, which can cause even more lower extremity weakness, problems with balance, decreased endurance, and even depression. The irony is that this cycle, which began with caution and a fear of falling, lends itself to exactly that. . .a fall.

Why are low-vision aging adults at higher risk for falls?

According to the CDC, “Each year, millions of older people-those 65 and older-fall. In fact, one out of three older people fall each year, but less than half tell their doctor. Falling once doubles your chances of falling again.” The typical aging adult with low vision faces challenges that others do not. Difficulty seeing details combined with reduced contrast sensitivity leads to a decline in mobility and socialization.

So how do we help older adults with low vision lower their risk for falling? When considering safety within the home, persons with low vision must make it a priority to add lighting & contrast whenever possible. Consider all rooms of the house, including entrances, hallways and stairways.

Placement of night lights in hallways, stairway, etc.

Keep flashlights in accessible places throughout the home where night lights are not possible.

Instead of closing blinds, keep them open & wear appropriate colored filters to manage glare/light sensitivity.

Small battery operated stick-on lights or rope lighting is inexpensive, and easy to place on steps to light up a stairwell.

Line edge of steps, or stairway railing with brightly colored duct tape to increase visibility.

Make sure grab bars, tub benches, shower chair are high contrast, to be most visible.

Remove throw rugs, with the exception of those providing function, such as the one at the entrance and bathtub. Their purpose is for providing dry shoes and feet, but they should have a non-skid back and a high contrast color to “stand out.”

Reduce clutter in rooms to increase safety by removing items from floors, walkways and stairwells.

Consider investing in a Medical Alert System to provide added piece of mind, confidence, especially when living alone.

Persons with low vision can decrease their frequency of falls by staying social and walking in the community. Unfortunately, many low vision adults become more house bound when they can no longer drive. Locating sources of alternative transportation may be helpful. Seeing faces is difficult, making socializing a challenge, which can lead to depression. The following recommendations take into consideration the challenges of not seeing details or across the visual field normally, while improving lower body strength, endurance, coordination, confidence, and hopefully reducing the risk of a fall.

Encourage regular trips to the grocery stores and the mall to keep physically fit. Malls are safe environments to walk around because of wide, straight hallways. Use magnifiers to see price tag/label details, or take advantage of personal shoppers who assist with locating items.

Participate in regularly scheduled exercise sessions (videos, groups, etc). Sit/stand in the front row, ask instructor to provide clear verbal instruction, instead of only demonstration. Consider hiring a personal trainer in order to get 1:1 instructions for how to use exercise equipment. If watching a video, move closer to your largest TV screen. Home exercise equipment can be labeled with high contrast markings to increase visibility of its details.

Consider joining a senior center in the community. Some have low vision support groups.

Access driving alternatives, such as the Smart Bus, Senior Centers, Local Volunteer or Church groups. Consider using money previously spent for a car and its expenses to hire a private driver.

Use appropriate colored filters in bright outside conditions or darker inside environments (i.e. Amber outside in the sun; Yellow inside a dark restaurant or outside with overcast weather).

Consider using a walker or support cane when walking longer distances in the community or neighborhood. Many individuals decline using an assistive device, not realizing how active and fit it can make them. Rolling walkers are even available with seats, allowing for rest breaks wherever necessary.

While the fear of falling is great amongst all seniors, those with low vision need to consider adding strategies that specifically benefit them. Making changes within the home may be as simple as improving lighting and contrast. Remaining physically fit outside of the home may be done with shopping or exercise equipment, but either way staying active will improve confidence, the fear of falling, and hopefully decrease the chance of a fall. If you are unsure of what approach is best for you, consult with your ophthalmologist about scheduling a low vision eye exam and occupational therapy.

Reference:
Centers for Disease Control and Prevention, National Center for Injury Prevention and Control-CDC 24/7: Saving Lives, Protecting People

12/3/15

Annette M. Babinski, OTR/L CLVT
Henry Ford Health System
Vision Rehabilitation Center

Michelle Buck, MS, OTR/L CLVT
Henry Ford Health System
Vision Rehabilitation Center

#GivingTuesday – Giving For Eye Research

Medical research funding from the US government, the medical device and pharmaceutical industries, biotech and foundations has dropped 0.8% per year, every year from 2007 to 2012. Even with the economic recovery, the funding of eye research from the NIH in 2014 decreased by 17% from 2012.

What makes this particularly disturbing is that the need for eye research is more important now than ever, as demonstrated by the infographic below.

Giving to eye research — This infographic by the National Institute of Health (NIH) is used with their permission.

Giving For Eye Research

The eye diseases in the above graphic are related to aging. The number of people being affected is more than doubling for each eye diseases, except for diabetic retinopathy which will increase by 47%, by 2050.

While we are more health conscious than in previous years, knowing the importance of exercise, healthy eating and not smoking, the US population is aging.

Aging baby boomers, the largest population group in US history, are creating a dramatic shift in the age composition of the U.S. population. It is projected that the entire senior population, including the pre-boomer silent generation, will reach 71.4 million people by 2029. This means that those people 65 and older will make up about 20%of the US population by 2029, up from almost 14% in 2012.

We need your help to find treatments and cures for these sight-threatening eye diseases.

December 1st will be the fourth year of #GivingTuesday. It is a global day of giving using combined power of social media and collaboration. Always the Tuesday following Thanksgiving, it has become as widely recognized as Black Friday and Cyber Monday and kicks off the philanthropic season, when many focus on their holiday and end-of-year giving.

We are asking that you support eye research through the Discovery Eye Foundation this philanthropic season with a gift on #GivingTuesday. It is easy to do; you can do it from the comfort of your home – just click here.

Also share this post with family and friends so they can also give the gift of sight this holiday season.

Thank you for reading our blog and for your support.

11/24/15

Susan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

Smoking and Your Eyes

Smoking is the single largest preventable cause of eye disease.

On the third Thursday of November each year, smokers across the nation take part in the Great American Smokeout, sponsored by the American Cancer Society. This might be the ideal time for you to stop smoking and ACS has information and resources you may find helpful.

Here are some things you should know about smoking and your eyes.

Smoking at any age, even in your teens or twenties, increases your future risk for vision loss.

The more you smoke, the higher your risk for eye disease.

If you quit smoking, your risk for these eye diseases decreases considerably.

Smoking increases your risk for cardiovascular diseases that indirectly influence your eyes’ health.

Women who smoke during pregnancy increase their chance for a premature birth and a potentially blinding eye disease called retinopathy of prematurity (ROP).

A smoker is two times more likely to develop macular degeneration compared with a nonsmoker.

Smoking double your chance of forming cataracts and the risk continues to increase the more you smoke.

Smoking doubles your diabetes risk which can lead to the blinding eye disease, diabetic retinopathy.

Smokers are more than twice as likely to be affected by dry eye syndrome as a non-smoker.

Second-hand smoke also makes dry eye worse, especially for contact lens wearers and post-menopausal women.

If you smoke you can have a three-fold increase in the risk of developing AMD compared with people who have never smoked.

Smoking appears linked to the development of uveitis with smokers having more than twice the risk of non-smokers.

If you are looking to stop smoking you may also want to check out Smokefree.gov which provides free, accurate, evidence-based information and professional assistance to help support the immediate and long-term needs of people trying to quit smoking.

11/19/15

Susan DeRemer, CFRE
Vice President of Development
Discovery Eye Foundation

Creating Cybrids to Study Age-Related Diseases

DEF Research Director Dr. M. Cristina Kenney’s research has shown that the mitochondrial DNA from different ethnic/racial populations may play a key role in determining that population’s resistance or susceptibility to disease (see previous article on 11/12/15 – Mitochondria and Age-Related Macular Degeneration). In order to study these effects, Kenney has developed the cybrid model using mitochondria from subjects of different ethnic/racial groups (Figure 1). The comparison of an individual’s mitochondria with that from other ethnic/racial groups (African, European, Asian or Ashkenazi Jewish) allows us to determine if their mitochondria determine that population’s susceptibility or resistance to disease and to response to drugs.

Personalized cybrids
Kenney’s cybrids are made with mitochondria from the blood taken from individual living donors. Looked at individually they are all really “personalized cybrids” because each cybrid test system has the mitochondria from the original donor and reflects the responses of that donor.

Using Cybrids to Study Age-Related Diseases

How is Kenney using these personalized cybrids?
Kenney is partnering with Dr. Pinchas Cohen, dean of the University of Southern California, Leonard Davis School of Gerontology, to explore how novel, small proteins produced from mitochondria might be used to treat a variety of age-related diseases such as age-related macular degeneration, Alzheimer’s, Parkinson’s, stroke and cholesterol. Cohen’s laboratory has discovered and characterized many of these new, small proteins called “mitochondrial derived peptides” (MDPs). His work has shown that these MDPs can protect brain cells from damage and early death, such as occurs in Alzheimer’s disease. Cohen and Kenney are now testing these MDPs in the K and H cybrids to assess their protective effects to stop retinal cell death, such as seen in AMD.

Kenney explains her approach:
“Our cybrid system represents a very powerful technique. We are now using the Ashkenazi Jewish population as an excellent model to learn how the mitochondria, with their unique mtDNA, influence the risk factors for AMD. We plan to extend the study to investigate Ashkenazi Jewish people’s susceptibility to Alzheimer’s disease, heart disease and stroke. Eventually, we believe the findings for the K haplogroup mitochondrial DNA will be applicable to other groups, as well.”

11/17/15

Anthony B. Nesburn, MD, FASC
President/Medical Director
Discovery Eye Foundation

Mitochondria and Age-Related Macular Degeneration

Research on mitochondrial DNA shows promise for treating AMD

For the past few years, DEF Research Director Dr. M. Cristina Kenney has been researching the relationship of mitochondria and age-related macular degeneration (AMD). She found that damaged mitochondria from people with AMD send signals that can cause retinal cells to die at an increased rate, compared with people who had healthy mitochondria and no AMD. That research led to the exploration of stimulating mitochondria to support retinal cell health in an effort to retain or restore vision for people with AMD.

Mitochondria in Cells
Cells are the basic building blocks of all living things. The human body is composed of trillions of cells. They provide structure for the body, take in nutrients from food, convert those nutrients into energy and carry out specialized functions. Cells also contain the body’s hereditary material (DNA) and so they can make copies of themselves.

Mitochondria are tiny structures inside cells whose function is to produce energy, like a battery in a flashlight, to keep cells alive. Each cell contains hundreds to thousands of mitochondria, which are located in the fluid that surrounds the nucleus. Although most DNA is packaged in chromosomes within the nucleus of a cell (nuclear DNA), mitochondria also have a small amount of their own DNA, known as mitochondrial DNA or mtDNA.

Because only egg cells contribute mitochondria to a developing embryo, only females can pass on the mitochondrial DNA to their children.

Mitochondrial Haplogroups
The mtDNA can be classified into categories called haplogroups, which represent different ancient, geographically separated groups of people. For example, African-Americans and people of ancient African lineage have inherited L haplogroup mitochondria from their mothers no matter where they currently live.

Similarly, most Ashkenazi Jewish populations (primarily those Jews whose families originated in Eastern or Central Europe) possess mitochondria of the K haplogroup. People with this haplogroup of mtDNA seem to be susceptible to a variety of age-related diseases, including age-related macular degeneration (AMD).

The incidence of AMD varies a lot among different ethnic/racial populations. For example, in the United States, the likelihood of losing vision from AMD is very low for a person with an African maternal background but it is much higher in people of European descent. Similarly, in an Israeli eye clinic, of the people who had AMD, 96% were Jewish while only 4% were of Arab descent. This suggests that European mtDNA in retinal cells of Caucasians may be the reason they are more susceptible to AMD.

Mitochondria and Age-Related Macular Degeneration — Figure 1

It has been recognized that AMD is a very complex disease with many factors involved (Figure 1). There are more than 30 genes associated with AMD, representing many different biological pathways. In addition, mitochondrial damage and specific mtDNA haplogroups have been associated with AMD. Finally, it is recognized that environmental factors, such as smoking and obesity, increase the risk to develop AMD.

Although millions of dollars and thousands of man-hours have been invested in finding the causes and treatments for AMD, we still do not understand how to prevent the most common form of AMD. One major difficulty has been that when we study a diverse group of individuals, each with hundreds of different nuclear and mitochondrial genes, it is very difficult to identify the causes and pathways involved with developing AMD and determining effective treatments. One drug may not help everyone and different people develop different types and severities of AMD.

Kenney’s approach to this dilemma has been to SIMPLIFY THE TESTING SYSTEM (Figure 2). In her research with different ethnic/racial groups, Kenney has found that the Ashkenazi Jewish population (K haplogroup) is an excellent group in which to study age-related diseases. This group has very well characterized nuclear and mitochondrial genes, the population tends to relatively homogenous and to marry within their community. Finally, the Ashkenazi Jewish population has longevity, which increases the likelihood that they will develop aging diseases, such as AMD.

Kenney’s laboratory has created a “cybrid” test system, which are cell lines with identical nuclei and nuclear DNA, but different mitochondrial DNA so that the differences in the cell behavior can be attributed to the different mitochondrial DNA (see the following cybrid story on 11/17/15). Using the cybrid system, Kenney has compared cell behavior of mitochondria from subjects with the K (Ashkenazi Jewish) haplogroups and the mitochondria from people of the H haplogroup (Figure 3), the most common European haplogroup.

There are:

Major differences in production of cholesterol and lipid molecules
Altered levels of inflammation
Differences in their responses to toxic effects of amyloid-? (a toxic protein associated with AMD and Alzheimer’s disease)

These differences are important contributors to AMD and other age-related diseases.

Significance of the Findings
Maternally inherited mitochondrial DNA can influence how a person’s cells respond to stress and this can contribute to age-related diseases. This is a completely new way of thinking about common aging diseases and offers new approaches to treatment and prevention of those diseases.

Future Studies
Kenney’s laboratory will continue to use the K haplogroup cybrid model to study the mitochondrial DNA, with the goal of blocking the harmful events that cause early retinal cell death, such as that seen in AMD. An additional advantage of cybrids is that they are unique to the donor whose blood was used to make them. Therefore with these “personalized cybrids,” Kenney can test the responses of the personalized cybrids to drugs that are currently being used for AMD (Lucentis™, Avastin™ and Eylea™). They can also be used to identify novel, new drugs that can protect the cells from early cellular death, a major event in the dry form of AMD. This research shows great promise in developing personalized treatments for AMD and other age-related diseases.

11/12/15

Anthony B. Nesburn, MD FACS
President/Medical Director
Discovery Eye Foundation

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