What Is Macular Degeneration (AMD)?

The function of your eye can be compared to the workings of a camera.  Just as the camera focuses light rays onto film to register a picture, the lens of your eye focuses light onto your retina to form an image.  The retina is a thin layer of tissue in the back of the eye.  Specialized cells in the retina convert light into electrical impulses, which are then transmitted to the brain.  If the film in your camera is defective, you will not get a perfect picture.  Similarly, abnormalities of the retina will affect how well you can see.

Macular degeneration is an age-related eye condition in which the specialized area of the retina responsible for sharp central vision and color discrimination (called the “macula”), is damaged.  
Despite its small size (about that of this “O”), the macula is 100 times more sensitive to detail than the rest of your retina.  As a result, macular degeneration sufferers often can no longer distinguish faces, clocks, printed words, street signs, or other objects “straight ahead” in the 
center of their field of vision. 

More than 13 million Americans age 40 and older have some signs of age-related macular degeneration (AMD), and one to two million have the more advanced, vision-threatening stages of the disease.  AMD is a leading cause of blindness in people over age 50.  The greatest risk factor is age.  AMD affects 11 percent of Caucasians ages 65 to 74, and 28 percent of Caucasians age 75 and older.  This “epidemic” is a major concern because, as our population ages, the number of people with AMD is expected to double by the year 2030.

Macular degeneration often starts with the appearance of drusen, yellowish-white deposits beneath the retina caused by the buildup of retinal waste products.  Drusen usually do not affect vision themselves and are frequently found with aging (similar to age spots).  However, if the drusen are numerous and appear in the center of the macula they can lead to progressive deterioration, including the development of severe macular degeneration.

Researchers are not certain what causes the changes in the macula that lead to the following types of degeneration.  Aging and heredity are the main culprits.

Other risk factors include:

• Long-term exposure to UV-light

• Low levels of certain nutrients

• Smoking increases risk 2-3 times

• Circulatory problems

• Lighter colored eyes

• Being a woman

• Being Caucasian

  Dry Macular Degeneration

The most common type of macular degeneration is associated with the aging process and is called “dry” macular degeneration.  This form accounts for the overwhelming majority of cases (about 80 percent) and is caused by a breakdown or thinning (atrophy) of the tissues in the macula.  This leads to a loss of vision cells in the macula, which can make objects appear washed out or difficult to see.  Fortunately, most “dry” cases are not associated with severe visual loss. 

  Wet Macular Degeneration

About 10 percent of AMD falls into a category called “wet” macular degeneration.  It is marked by the growth of new abnormal blood vessels under the macula, which can leak fluid and blood.  This leakage may create scar tissue, resulting in a blind spot that causes a rapid and profound loss of sharp central vision.    “Wet” macular degeneration is more rare than other forms but, of all patients legally blind from AMD, the vast majority have this type.  The earlier it is detected, the better the chances for preserving vision. 

  Other Forms of Macular Degeneration

Less common reasons for damage to the macula include injury, infection, inflammation, marked nearsightedness, hereditary factors and drug toxicity.

Since images outside of the blurred area are often still visible, macular degeneration may result in legal (less than 20/200 vision), but not total blindness.  People are usually able to perform most of their daily activities and take care of themselves by using their remaining side (or “peripheral”) vision.

Macular degeneration usually develops gradually and painlessly.  It can cause different symptoms in different people.  If only one eye is affected, the disease may be difficult to detect in its early stages.  Good vision in one eye can often mask visual difficulty in the other eye.  As the condition progresses, however, a number of symptoms may become more obvious, including:

• Difficulty reading or doing close-up work  (type may appear blurred)

• Distortion of vertical lines (for example, door frames, 
  sides of buildings and streetlight posts may appear wavy)

• Dark spots or empty spaces appear to block 
  the center of the field of vision causing blind spots

• A gradual “graying” or haziness of vision

• The center of a scene appears smaller than the rest 

• The size of objects appears different for each eye 

• Colors don’t look the same for each eye or are hard to distinguish or dim

If you suddenly notice any of these symptoms, you should see an eye care specialist as soon as possible.  Do not assume you simply need a new pair of glasses and then wait to make an appointment for the future. 

You can test for early warning signs of macular degeneration with a simple, inexpensive and effective screening tool called the Amsler Grid.  A normal, healthy eye sees the grid pattern (shown below) in its entirety, without distortion.  An eye with macular degeneration, however, may see the lines as distorted or bowing toward the center, or may have a shadowy spot at the point of focus or entire areas that are missing.

People diagnosed with macular degeneration should do this test daily or at least several times a week.  This is especially important for detecting and treating cases where the dry type of macular degeneration changes into the more severe wet type.

How to Use the Amsler Grid

1. View the grid from 12 to 16 inches away—either held at a comfortable reading distance or taped 
   to a well-lit wall, refrigerator or cabinet door.

2. If you normally wear glasses for reading, use them.  If they are bifocals, look through the bottom, or reading, portion of the lens.

3. Cover your left eye (do not press on it) while continuing to look at the dot with your right eye.  Do not move your gaze from the dot.

4. While looking at the center, note if all the
   lines are straight and squares the same size.  
   Check for any distortion, blurriness, 
   discoloration or other abnormalities.

5. Repeat the test with your right eye.

If you notice any problems or changes, contact your eye care specialist immediately.

A complete eye examination is necessary to evaluate the presence of macular degeneration and to determine whether treatment would be beneficial.  At Eye Care Specialists, the following instruments and tests may be used.

  Slit Lamp:  With this special microscope, we can see inside your eye to evaluate its overall health.  In addition, by using a special lens with the slit lamp, we are able to conduct a detailed examination of the macula. 

  Amsler Grid test:  This self-test (see previous page) helps to detect subtle and early changes in your vision that may be caused by macular degeneration.

  Ophthalmoscope:  This instrument allows us to check the 
health of your optic nerve and retina for any abnormal conditions, 
such as AMD or retinal detachment.

  Fluorescein Angiogram:  This relatively painless, in-office test involves injecting a fluorescein dye into an arm vein.  Once the dye reaches the blood vessels inside the eye, a special camera takes a rapid series of pictures (not x-rays).  The retina is the only part of the body where blood vessels can be seen directly.  Because any new or abnormal retinal vessels leak the dye, fluorescein pictures can be used not only for the diagnosis and classification of  AMD, but as a “roadmap” for treating leaky vessels with the laser.

  Dry Macular Degeneration

Currently, there is no treatment for this more common type of AMD due to a lack of understanding of its causes and difficulty in observing its slow progression.  The use of vitamins and avoidance of risk factors (described later in another section) may prove beneficial.  Because dry AMD usually does not result in rapid vision loss, many patients retain good sight throughout their lives.  Some, however, can experience a significant loss of central vision over time.  These people usually benefit from magnifiers and other low vision aids.

  Wet Macular Degeneration

A portion of patients with this less common type of AMD can be helped by laser treatment
—if the condition is promptly diagnosed and abnormal vessels are in a treatable location.

g  Traditional Laser Therapy   

A focused beam of intense laser light is used to heat up and seal off leaking blood vessels.  This produces tiny scars, which halt the spread of damage to the retina.  Because laser “cauterization” makes permanent scars, it must be used carefully near the center of vision—where vessels often are not treatable because they are too extensive or in the wrong location.

Laser treatment is fast, virtually painless, and can be done in an office/outpatient setting using topical (drops) or local (injection) anesthesia.  Weeks to months after the procedure, fluorescein angiography may be repeated to evaluate effectiveness and any need for more treatment.  Periodic eye exams are also required, since new abnormal blood vessels can reappear at any time.

It is important to understand that traditional laser treatment does not cure AMD and only rarely improves vision.  Instead, it is about 50 percent successful at stopping progression of the disease and preserving existing vision, and the effects are often temporary.   

g  Photodynamic Therapy (PDT)

With this new procedure, a light-activated dye is injected into the patient.  When the dye concentrates in newly growing blood vessels under the macula, the surgeon shines a “cold” beam of laser light onto the dye—causing it to release substances that seal off the leaky blood vessels without damaging the retina.  PDT frequently requires retreatment and has only limited application for patients with recent onset wet AMD and abnormal vessels that are easy to see.  PDT usually does not improve vision; it strives to stabilize or slow loss in about 60 percent of patients.

g  Ocular Injections

Some forms of wet AMD are not likely to respond to PDT due to the type and size of leakage pattern.  In these cases, injection of anti-angiogenic drugs (Avastin, Kenalog or Macugen) into the ocular cavity may provide the best possible outcome.  The goal of this treatment is to prevent further loss of vision; however, there is no guarantee.  Repeat injections may be necessary.  Your eye care specialist will determine if you are a viable candidate for this treatment.

g  Transpupillary Thermotherapy (TTT)

This new techniques uses an infrared laser to gently heat the back of the eye.  This causes localized hyperthermia—an effect similar to a high fever, which triggers a natural healing mechanism that results in the closure of the leaking blood vessels.  TTT is more promising than traditional laser treatment because its lower levels of radiation absorption are less likely to damage other parts of the eye.  Studies have shown stabilization of vision in 50-75 percent of patients.  Beneficial effects can take several months to see.

g  Macular Translocation Surgery

For select patients with no other options, this complicated treatment involves carefully moving the macula away from new abnormal blood vessels and rotating it above healthy retinal tissue.  This surgery is rarely used since results vary widely. 

  On the Horizon . . .

Research is being conducted into embryonic cell transplantation and implanting tiny telescopes or 
bionic camera chips into the eye.  It is hoped that within 10 to 25 years, these or other treatments 
will effectively serve all AMD patients.

A National Eye Institute Age-Related Eye Disease Study (AREDS) has found that high levels of antioxidants and zinc can reduce the risk of developing advanced AMD by about 25 percent and the risk of related vision loss by about 19 percent.  Although these nutrients cannot cure AMD or restore sight, study results suggest they may be key to protecting and preserving existing vision for patients with either wet or dry degeneration.

Who should take these nutrients? 
People diagnosed as being at risk for advanced macular degeneration should strongly consider a supplement that matches the AREDS dosage.  Although it currently has not been documented, 
it may also be helpful for patients with mild or moderate AMD to take lower dose supplements, 
like “Ocuvite with Lutein.”  Upon careful dilated examination, your eye doctor can let you know which, if any, of these applies to you.

What dosages were used in the study?  

Beta-carotene       15 mg
Vitamin C            500 mg
Vitamin E            400 International Units
Zinc                    80 mg as zinc oxide
Copper*                2 mg as cupric oxide

*Copper was added to the formulation to prevent copper deficiency, 
  which may be associated with high levels of zinc supplementation.

Where can I find this supplement?  
Bausch & Lomb, an eye care company, provided the AREDS formulation.  They market it as a tablet called "Ocuvite PreserVision" through pharmacies and retail outlets.  Other companies are expected to sell similar formulations.  Antioxidant vitamins and zinc can also be purchased separately; however, to avoid any overdosing or copper deficiency, check with your doctor before using.

What if I already take a multivitamin?  
Multivitamins and/or diet alone can’t achieve the high levels of nutrients in the study.  
Most AREDS participants took both a multivitamin and the supplement. 

What are the potential side effects?  
The 4,757 AREDS participants aged 55-80 reported few side effects. About 7.5 percent of those assigned to zinc treatments (compared with five percent who weren’t given zinc) experienced urinary tract problems that required hospitalization, including infections, kidney stones, incontinence and enlarged prostate.  Zinc-takers also reported more anemia; however, testing showed no difference between groups.  Yellowing of the skin, a known side effect of large doses of beta-carotene, was also sometimes reported. 

Should I be cautious about using these nutrients and doses?  
Yes.  Many people, especially older adults, use a variety of prescription medications, over-the-counter drugs, dietary supplements and herbal medicines.  High-dose vitamins and minerals like the AREDS formulation can interfere with these medications or decrease the absorption of other nutrients in the body—ultimately affecting a person's nutritional and health status. 

For example, beta-carotene has been shown in two National Cancer Institute studies to significantly increase the risk of lung cancer in smokers.  As a result, smokers should check with their doctor before taking the AREDS formulation.  Also, high doses of zinc may cause copper deficiency and, therefore, need to be balanced with increased copper intake.  Generally, any self-medication with high doses of vitamins and minerals is not recommended, especially for people with cancer, diabetes and heart disease. 

If you plan to take eye-related nutrients, discuss it (and whatever else you take) with your doctor, eye specialist and/or pharmacist to determine which formulation and dosages are best for you.

The following measures may help you to “see” life to the fullest:

• Schedule regular dilated eye exams
  (every 2 years over the age of 50; every year if you have early AMD)

• Use the Amsler Grid self-test (daily if you already have AMD)

• Eat a balanced diet (some studies show that lutein and 
  zeaxanthin--found in eggs, corn and spinach--may help protect your retina)

• Wear UV-blocking sunglasses (studies have linked ultraviolet light exposure 
  with the development of AMD and cataracts)

• Control other diseases, like high blood pressure and circulatory problems

• Don’t smoke

Losing sight to AMD does not inevitably mean losing your way of life. By using their remaining side vision, along with a variety of coping techniques and tools, most people are able to lead independent, productive lives pursuing their goals and interests.  The key is to reach out and take advantage of the many resources that are available, including the support of friends and family. 

Our office can suggest where to obtain special lamps, magnifiers, eyeglasses, large-print publications and other aids.  We also have access to a new, lighted magnifying device that can plug into your TV to enlarge words on a medicine bottle, magazine pages, or anything else you wish to show on your screen. 

We also strongly urge you to contact the following organizations for counseling; needs assessment; low vision aids; and help with obtaining Social Security/veterans benefits, income tax exemptions, and handicapped parking designations or transportation services.  Some groups even offer in-home visits to show you ways to make tasks easier and safer.

The most satisfied patients are those who are educated, active partners in their own care.  As such, we encourage you to ask questions and stay abreast of new developments that may improve or protect your vision.  And, we remind you that keeping your eye appointments is essential to ensuring that you have every opportunity to see life to the fullest.

Help is just a call away at:

• Badger Association for the Blind
  912 N. Hawley Rd.
  Milwaukee , WI   53213    
  414-258-9200  
  

• National Society to Prevent Blindness--Wisconsin Chapter
  759 N. Milwaukee St.
  Milwaukee , WI   53202    
  414-765-0505
  

• State of Wisconsin Bureau for the Blind (& Visually Impaired)
  414-302-2762 or 888-879-0017 (toll free)
  (In addition to making home visits, this organization sets up local support groups)  
  

• American Foundation for the Blind
  15 West 16th St .               
  New York , NY   10011    
  800-232-5463
  www.afb.org
  (Offers low vision products & the excellent  “Making Life More Livable: Simple Adaptations for Living at Home After Vision Loss” guide)  
  

• The National Eye Institute 
  301-496-5248
  www.nei.nih.gov/amd

If you would like a detailed color booklet with the information contained in this section and/or to schedule a comprehensive evaluation for macular degeneration, please feel free to contact Eye Care Specialists’ Communications & Education Department at 414-321-7035.