CONDITIONS

Age-Related Macular Degeneration

What Is Age-Related Macular Degeneration

Age-Related Macular Degeneration, or AMD, occurs when the macula, an area of the retina that allows you to have detailed central vision, breaks down. It does not affect peripheral vision, which is the ability to see general shapes “out of the corner of your eye” even when you’re looking straight ahead. The macula is made up of millions of light-sensing cells that provide sharp, central vision. It is the most sensitive part of the retina, which is located at the back of the eye. The retina turns light into electrical signals and then sends these electrical signals through the optic nerve to the brain, where they are translated into the images we see. When the macula is damaged, the center of your field of view may appear blurry, distorted, or dark.

There are two main types of AMD:

  • Dry AMD (atrophic, non-neovascular) is the most common form. In Dry AMD, the tissues of the retina thin over time and small pieces of fatty protein develop under the retina, causing vision loss to occur gradually.
  • Wet AMD (exudative) only affects about 10% of patients with AMD. Typically, the condition develops in people who already have dry AMD. Wet AMD creates more damage than dry AMD and progresses more quickly as blood vessels grow under the retina and leak fluid or blood (exudate).

Age-Related Macular Degeneration (AMD) is the leading cause of permanent impairment of reading and fine or close-up vision among people aged 65 years and older, according to the Centers for Disease Control (CDC). The CDC estimates that 1.8 million Americans aged 40 years and older are affected by Age-Related Macular Degeneration (AMD). Another 7.3 million Americans who have large deposits in the retina called drusen, are at increased risk of developing AMD. By 2020, due to our aging populations, the number of Americans with AMD is predicted reach an estimated 2.95 million.

What Causes Age-Related Macular Degeneration

There are two main factors that cause AMD:

  • Heredity. Recent studies have shown that genetic changes are the cause of about 50% of the cases of AMD, both dry and wet. Certain types of AMD are also found to run in families.
  • Aging. Atrophy means wasting away or deteriorating. This can happen with many tissues and organs in the body as we age. In the eye, atrophy or thinning of the macula gradually causes Dry AMD in some people. One study showed that the risk of getting macular degeneration rises from around 2 percent for people in their 50s to nearly 30 percent for people over age 75.

Risk Factors For Age-Related Macular Degeneration

There are several factors that can influence the risk of developing AMD:

  • Oxidative stress. As our bodies interact with the oxygen in the environment, molecules called free radicals are formed. These can damage  cells throughout the body, including the eye, and are thought to play a role in the development of AMD. About one-third of Caucasians are genetically more prone to oxidative stress and with it, AMD.
  • Inflammation. This function of the immune system is meant to fight off infection. However, an overactive immune system has been linked to the development of AMD.
  • Smoking. Smokers are up to four times more likely to develop AMD than non-smokers.
  • High blood pressure. Scientists have found a link between high blood pressure and AMD. Most recently, researchers discovered a possible link between the use of certain high blood pressure medications (vasodilators) and an increased risk of developing AMD.
  • Obesity. Studies have shown that obese individuals are more than twice as likely to lose their vision.
  • Heredity. AMD has been shown to run in families, and is thought to have genes specific to an increased AMD risk.
  • Aging 

Diagnosing Age-Related Macular Degeneration

If you or your doctor notice changes in your vision that suggest an eye disease or condition, you may be referred to an ophthalmologist (medical doctor specializing in the eye) for diagnosis. The early and intermediate stages of AMD usually start without symptoms. Only a comprehensive dilated eye exam can detect AMD. Below are the leading methods of diagnosis for eye diseases and conditions:

One of the first tests done may be a visual acuity test. Using an eye chart, your eye care professional can measure how well you see at distances. Other tests are more specific to the type of AMD suspected.

Dry AMD

  • Dilated eye exam.. During dilated eye exams, special eye drops are given to patients to dilate, or widen, the pupil. The widening of the pupil allows for more light to enter the eye, giving doctors a better view of the workings of inner eye components, like the retina. The drops take about twenty minutes to have their full effect. Once the pupil is fully dilated, the doctor can examine the eye with an ophthalmoscope, a specially designed optometric instrument to view the retina and other areas of the back of the eye. If he or she detects macular degeneration, an amsler grid (see below) can be conducted. The dilation caused by the drops can last for several hours following the exam, and typically results in temporarily blurred vision. If you are planning to drive to the doctor’s office, you may want to ask a family member or friend to accompany you in the event that your blurred vision lasts longer than expected and you are unable to drive home.
  • Amsler grid.If the doctor detects macular degeneration based on described symptoms or an ophthalmoscope examination, you will be asked to look at a chart called the Amsler Grid to check for AMD symptoms such as dark, wavy, or blurry areas in your range of vision. With AMD, typically only your central vision will be changed. Changes in your central vision may cause the lines in the grid to disappear or appear wavy, a sign of AMD.

Wet AMD

  • Fluorescein angiogram.An ophthalmologist, or eye doctor, performs this test by injecting a fluorescent dye into your arm. Pictures are taken as the dye passes through the blood vessels in your eye, which allows your doctor to see leaking blood vessels that occur in a severe, rapidly progressive type of AMD. In rare cases, complications to the injection may arise, from nausea to more severe allergic reactions.
  • Optical coherence tomography.OCT s a non-invasive imaging test using light waves to take pictures of your retina that may reveal abnormal blood vessels and macular damage contributing to wet AMD. Ultrasound, which uses sound waves to capture images of living tissues, is similar to how OCT test works, except that it uses light waves. An OCT can achieve very high-resolution images of any tissues that can be penetrated by light—such as the eyes. The light beam used for the OCT test is painless. Your eyes will first be dilated. Then you will be asked to place your head on a chin rest and hold still for several seconds while the images are obtained.
  • Fluorescein angiography. In this test, a fluorescein dye made of food coloring and fluoresces (naturally ‘glowing’ particles) is injected into a vein in your arm. Because of its fluorescent properties, the dye is able to be photographed as it travels to the eyes and through the retinal blood vessels, revealing any abnormalities that could be signs of wet AMD. Dye components put people who have allergies to shellfish and/or iodine at a higher risk of complication from this test, so be sure to let your doctor know of any food or medication allergies. Properly prescribed antihistamines may be able to prevent allergic reactions.

Symptoms of Age-Related Macular Degeneration

The following are symptoms of age-related macular degeneration:

  • Dry AMD. In the early stages, the condition is almost always without any symptoms. As damage occurs over time, the fine detail of central vision you use for reading and threading a needle will become blurry, dark or even blank. Side vision (peripheral) will is not affected. You might not notice vision changes if only one eye is affected. The other eye will compensate. Dry AMD symptoms progress fairly slowly.
  • Wet AMD. You may notice all of the above as well as crooked images and the fact that the size of images is different for each eye and color don’t look that same with each eye. Wet AMD symptoms progress very rapidly and require immediate medical attention.

Prognosis

Macular degeneration almost never causes total blindness. Even people with more advanced cases of AMD retain their peripheral (side) vision and can learn to compensate. In many cases, macular degeneration’s impact on your vision can be minimal.

Living With Age-Related Macular Degeneration

In many cases, depending on the eye disease or condition you have and your response to treatment, your vision may not be not noticeably impaired and you won’t experience any pain or only mild discomfort.

However, you may need to compensate for partial loss of vision if you have a condition such as wet AMD that can’t be treated. Ask your eye care specialist about low-vision rehabilitation devices and services that will help you learn coping strategies so that you can to continue to live independently.

Many people with some vision loss have to stop driving. If that happens to you, visit SeniorDrivingAAA.com to get information about affordable and convenient ways to maintain your mobility.

Here are some top tips for living well with vision impairment:

  • To wake up, a person may use a talking watch or talking alarm clock.
  • To get dressed someone may have their own system of identifying clothes and colors. They might use safety pins to match the same color outfits together, or use Braille clothing tags.
  • Instruction is available for visually impaired people to learn independent meal preparation skills. Special dots or Braille can be put on conventional and microwave ovens to aid in instruction and use.
  • Someone with low vision might use a dark tablecloth with light colored dishes and a light tablecloth for dark dishes. Contrasting colors help individuals who have some remaining vision better see where things are.
  • Similarly, someone with low vision might use dark mugs or glasses to pour light colored liquid such as milk and light colored mugs or cups to pour coffee or other dark liquids such as tea or hot chocolate.
  • To locate keys, wallet or purse, they might make an effort to put them in the same place all the time so they can be found more easily.
  • For leisure activities a person can watch audio described movies, listen to recorded books called Talking Books, play cards or other adapted games with friends.

Screening

Serious eye diseases and conditions often have no symptoms until irreversible damage to vision has been done. If you wear prescription glasses and/or contacts, you probably go to an optometrist for an annual check-up to make sure your prescription hasn’t changed and to order a new batch of contacts if you’re running out of them. Optometrists conduct vision tests to check for basic vision impairment, and can prescribe glasses and contact lenses. They can also spot early warning signs and give you a referral to an ophthalmologist, an eye doctor with a medical doctor degree, for a more thorough examination. If you do not wear contact lenses or glasses, chances are you miss out this periodic optometric screening. Many times, family doctors with conduct a visual acuity test, which is a series of letters decreasing in size on a chart that patients are asked to read to the best of their ability. This gives doctors the opportunity to do as the optometrists would.

The standard recommendation for all adults over the age of 40 is to have an eye exam at least every two years, and for adults over 65, to have an eye exam every year.  According to the National Federation of the Blind, prompt detection and treatment can preserve your vision for a lifetime even if you do contract a serious eye condition or disorder. Schedule an eye exam with an optometrist. If he or she spots any problems that may be of concern, you will most likely be referred to an ophthalmologist, a medical doctor specializing in eyes, for further testing. Be sure to make an appointment with the ophthalmologist and follow recommendations regarding the frequency of follow-ups should any diseases or conditions be detected.

People with diabetes or at risk of developing gestational diabetes are recommended to get additional ophthalmic screening.

The American Academy of Ophthalmology recommends the eye screening schedule:
       Type 1 Diabetes: Within five years of being diagnosed and yearly thereafter.
       Type 2 Diabetes: At the time of diagnosis and yearly thereafter.
       During pregnancy: During the first trimester and follow-ups if indicated.

Prevention

The best defense against AMD is to have regular checkups, because eye diseases do not always have obvious symptoms. Early detection and treatment are the keys to preventing vision loss. Beyond that, a healthy diet that has sufficient vitamins and other nutrients will help keep your eyes healthy, lubricated, and free of infections. Also, avoid second hand smoke—and if you smoke, kick the habit. Protect your eyes from injury by wearing plastic eye guards if you’re involved in any activity that poses a risk of flying objects or particles. Finally, remember that overexposure to the sun is just as bad for your eyes as it is for your skin. Wear sunglasses and stay away from tanning beds.

Medication And Treatment

  • Dry AMD According to Eyesmart.org, a service of the American Academy of Ophthalmology; there is no single treatment for the dry form of macular degeneration that works in all cases. However, the Age-Related Eye Disease Study 2 (AREDS2) showed that taking a dietary supplement of vitamin C, vitamin E, lutein and zeaxanthin, along with zinc, lowered the risk of dry AMD progressing to Wet AMD for some people. The supplements did not appear to benefit people with minimal macular degeneration.

Here is what was in the dietary supplement that was tested in the study:
•   Vitamin C – 500 mg
•   Vitamin E – 400 IU
•   Lutein – 10 mg
•   Zeaxanthin – 2 mg
•   Zinc oxide – 80 mg
•   Copper (as cupric oxide) – 2 mg (to prevent copper deficiency, which may be associated with taking high amounts of zinc)

Another large study showed that taking folic acid and vitamins B6 and B12 benefited women with AMD. Remember, however, that vitamin supplements don’t cure AMD or give you back any vision that has been lost.

  • Wet AMD The American Academy of Ophthalmology lists the following treatments that may reduce but not eliminate vision loss:
  • Anti-VEGF medication injection treatments. The injections contain drugs such as Avastin, Lucentis, and Eyelea that target a chemical called vascular endothelial growth factor (VEGF) in your body. VEGF causes abnormal blood vessels to grow under the retina.

In some cases, your ophthalmologist may recommend combining anti-VEGF treatment with other therapies:

  • Laser treatment. This is an outpatient procedure in the doctor’s office or at the hospital. A high-energy beam of light creates a small burn on the retina, destroying the abnormal blood vessels and preventing further leakage and growth.
  • Photodynamic therapy (PDT). This therapy uses a light-activated drug called a photosensitizer and a low-power, or cool, laser. The doctor injects the drug into a vein in your arm. It travels to the abnormal vessels behind the central macula and the low-power laser activates the drug, which causes damage to the unwanted blood vessels. Multiple treatments may be necessary.

Complementary and Alternative Treatment

The National Center for Complementary and Alternative Medicine (NCCAM) notes that a follow-up to the NIH Age-Related Eye Disease Study found the following results regarding proposed changes to a supplement containing high doses of vitamins C and E, beta carotene, and zinc that may delay the progression from dry AMD to wet AMD:

  • Adding omega-3 fatty acids (fish oil) did not improve the effectiveness of the supplement combination.
  • Reducing the amount of zinc or omitting beta-carotene from the supplements did not decrease their effectiveness.
  • Adding lutein and zeaxanthin (two carotenoids found in the eye) to the supplements improved their effectiveness in people who were not taking beta-carotene and those who consumed only small amounts of lutein and zeaxanthin in foods.
  • The results also suggested that the supplements might be improved by substituting lutein and zeaxanthin for beta-carotene.

Care Guide

A healthy, body, mind and spirit will improve your chances of controlling any eyes diseases and conditions you may have, especially as you age. Here are some guidelines for a lifestyle that will help you live not only long but well and go a long way toward preserving your vision for a lifetime:

 

  • Protect your eyes from injury. Don’t let an accidental injury threaten to rob you of you vision! If you do any type of chores such as carpentry, splitting logs for the fireplace, or even hanging a picture, wear an inexpensive plastic eye guard available at hardware stores.
  • Wear sunglasses. UV rays are dangerous. Remember that the rays shine through even on cloudy days.
  • Stop smoking. Smoke particles are irritants for the eyes and can cause inflammation and redness. Try cessation aids or join an online support group.
  • Eat real food. Make (and keep!) a resolution to avoid packaged and processed junk food and well as fast food. Opt instead for vegetables and fruits, lean protein from fish and chicken, the occasional serving of red meat, and whole grains. Skip the sugar except for special occasions and go easy on the salt.
  • Drink in moderation. The standard recommendation is no more than one drink a day for women and two for men. That amount has actually ben shown to improve your health – but there’s no need to start if you don’t drink at all!
  • Exercise regularly. No need to join a gym. Walking for 30 minutes three times a week will do the trick.
  • Get enough sleep. A regular sleep schedule, even on weekends and holidays, will train your body so that you avoid insomnia.
  • Be social. Especially if you’re suddenly single after a divorce or the loss of a loved one, make every effort to find groups and activities that surround you with people who care about you. The same goes for empty nesters.
  • Visit your healthcare providers for check-ups. Make appointments with your PCP, your dentist, any specialists on your team – and of course your eye care professional!

When To Contact A Doctor

In addition to your regularly scheduled visits to your eye care professionals, get immediate medical attention if you notice any sudden change in your vision or experience unusual symptoms such as extreme eye pain, burning, itching, redness, or fluid coming out of your eye.

Questions For A Doctor

Before you visit your doctor, write down a list of questions and concerns. Consider bringing a friend or family member along who can help you make sure you get all the information you need. In addition, writing down the doctor’s answers and recommendation for later reference is a good idea. Also come prepared with your medical history, information about any allergies you have, your family medical history, and a complete list of all medications you take including over-the-counter herbs and supplements.

Here are some questions you might pose when you visit your optometrist:

  • I started having trouble reading up close not long after I turned 40 so I bought a pair of readers at the drugstore. Is that OK? And did I pick the right strength?
  • I’ve always been nearsighted. Do I now need bifocals or progressive lenses?
  • I’ve heard about progressive contact lenses and monovision lenses. Would one of those options be right for me?
  • My eyes feel dry even when I blink. Is that a sign of a condition I’ve heard about called dry eye?
  • My eyes tear in cold weather, especially when it’s windy out. Is that a bad sign?
  • I work at a computer all day. Is that a risk for eyestrain?
  • Has my prescription changed in the last year? If so, is that a bad sign?

Here are some questions you might pose if you are referred to an ophthalmologist:

  • Which eye diseases or conditions are you screening me for?
  • If you diagnose an eye disease or condition, how much will medication and/or surgery cost?
  • Will the treatments control my problems so that I retain my vision?
  • How often will I need to come back to you for check-ups?
  • Should my adult children be checked if my condition is hereditary?
  • Are there any lifestyle changes I can make that will help prevent other eye diseases or the progression of the ones I already have?

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