Macular Degeneration

Macular degeneration begins when the central portion of the retina, the macula, begins to deteriorate. There are two forms of AMD. Each damages vision in its own way. The two forms are:

• Dry AMD: Dry AMD causes most cases (about 90%) of AMD. However, it only accounts for 10% of all blindness from AMD.

• Wet AMD: The situation with wet AMD is exactly the opposite: it causes only 10% of AMD but accounts for 90% of all blindness from AMD. 

How is AMD diagnosed?

AMD is detected during a thorough eye examination that includes:

• Visual acuity test: This eye chart test measures how well a person sees at various distances.
• Pupil dilation: This examination enables your doctor to see more of the retina and look for signs of AMD. To do this, drops are placed into the eye to dilate (widen) the pupil. After the examination, the patient’s vision may remain blurred for several hours.
• Tonometry: This is a standard test that determines the fluid pressure inside the eye. Increased pressure is a possible sign of glaucoma, another common eye problem with people over age 60.
• Drusen: One of the most common early signs of AMD is the presence of drusen. Drusen are tiny yellow deposits in the retina. The doctor can see them during an eye examination. The presence of drusen alone does not indicate a disease, but it might mean that the eye is at risk for developing more severe AMD.
• Amsler grid: (Link to the Amsler Grid; already on website) While conducting the examination, your doctor may ask you to look at an Amsler grid. This grid is a pattern that resembles a checkerboard. The patient covers one eye and stares at a black dot in the center of the grid. While staring at the dot, the patient may notice that the straight lines in the pattern appear wavy. This can be a sign of wet AMD.
• Fluorescein angiography: If the doctor suspects the patient has wet AMD, the patient may need to have a test called fluorescein angiography. In this test, a special dye is injected into a vein in the arm. Pictures are then taken as the dye passes through the blood vessels to determine whether they can be treated.

 
Who is most likely to develop AMD?

Factors that influence the risk for developing AMD include:

• Age: Age is the most powerful risk factor. Although AMD can occur during middle age, the risk of developing the condition rises sharply thereafter. People in their 50’s have about a 2% chance of contracting AMD. This likelihood rises to nearly 30% over age 75.
• Gender: Women tend to be at greater risk than men.
• Smoking: Smoking increases the risk of AMD.
• Family History of AMD: People with AMD in the family are at higher risk of developing the disease.
• Cholesterol: People with elevated levels of blood cholesterol may be at higher risk for wet AMD.

What happens in dry AMD?

In the dry form of macular degeneration, a yellow material begins to collect beneath the retina. This yellow material accumulates in tiny spots called drusen. At this point, patients may become aware of blurring of their central vision. Also, in dry AMD, the light sensitive cells in the macula slowly break down. With less of the macula functioning, central vision diminishes. Dry AMD often occurs in just one eye at first. Later, the other eye can be affected. Doctors have no way of knowing if or when both eyes may become involved. The cause of dry AMD is unknown.

What are the symptoms of dry AMD?

Dry AMD does not cause pain. The most common symptom of dry AMD is slightly blurred vision. The person may need more light for reading and other tasks. Also, the patient may find it hard to recognize faces until the person is very close to them. As dry AMD worsens, the individual may see a blurred spot in the center of their vision. This spot occurs because a group of cells in the macula have stopped working. Over time, the blurred spot may get bigger and denser, taking more of the patient’s central vision.

People with dry AMD in one eye often do not notice any changes in their vision. With one eye seeing clearly, they can still drive, read, and see fine details. Some people may notice changes in their vision only if AMD affects both of their eyes.

What is wet age-related macular degeneration (AMD)?

In the wet form of macular degeneration, abnormal blood vessels grow under the retina. These vessels bleed, which may cause central vision to be distorted or destroyed.

As you may know, wet AMD is a chronic condition of the eye that causes central vision loss. It affects your central vision, which is the center area of what you see. In fact, most of the things we do everyday, such as drive, read, or even watch TV, require central vision. This central vision loss from wet AMD is caused by damage of the retina, otherwise known as the macula.

For some people, wet AMD progresses slowly. For others, it may progress faster. AMD is a major cause of central vision loss in Americans aged 55 or older. When you’ve lived your life being able to do the things you wanted to, when you wanted to, central vision loss can leave you missing more than just your sight.

Macular degeneration can be treated in many ways, and numerous modalities are available and becoming available due to continuous research being done in this field. Our doctors perform all of the state of the art treatments for macular degeneration, in addition to surgery.

1. Usually the first line of treatment for the wet form of AMD would be Intra-vitreo injections using Lucentis, Avastin, Macugen, or steroids (see below for a description of each one). Often, combination therapy is an option. We are participating in a Level IV trial which assesses the efficacy of combination therapy with some of the above.
2. PDT (Visudyne) and Thermal Laser are other options in some cases. Often, combination therapies are also chosen.

LUCENTIS™

Lucentis™ (ranibizumab injection), is a prescription medicine for the treatment of patients with wet age-related macular degeneration (AMD). Lucentis™ has been shown to maintain or improve vision in wet AMD.

Lucentis™ is injected directly into the eye. Currently, the drug is supposed to be given every month for the rest of a patient’s life. Not all patients need such frequent treatments, however.

Who is Lucentis™ for?

Like any prescription medication, Lucentis™ is not for everyone. You should not use Lucentis™ if you have an infection in or around the eye. Like other injections given into the eye, serious eye infection and detached retina have occurred with Lucentis™. Increases in eye pressure have been seen within 1 hour of an injection. Your eye doctor will carefully monitor your eye pressure and eye health during the week after every injection.

Although uncommon, conditions with certain blood clots (arterial thromboembolic events) may occur.

Serious side effects related to the injection procedure are rare. These included serious eye infection, detached retina, and cataract. Other uncommon serious side effects included inflammation inside the eye and increased eye pressure.

The most common side effects were red eye, eye pain, and small specks in vision.

AVASTIN™

Avastin ™ (bevacizumab) was not initially developed to treat your eye condition. Based upon the results of clinical trials that demonstrated its safety and effectiveness, Avastin™ was approved by the Food and Drug Administration (FDA) for the treatment of metastatic colonrectal cancer. As a condition of approval, the manufacturer produced a “label” explaining the indications, risks, and benefits. The label explains that Avastin™ works by blocking a substance known as vascular endothelial growth factor or VEGF. Blocking or inhibiting VEGF helps prevent further growth of the blood vessels that the cancer needs to continue growing.

Ophthalmologists are using Avastin™ to treat AMD and similar conditions since research indicates that VEGF is one of the causes for the growth of the abnormal vessels that cause these conditions. Some patients treated with Avastin™ had less fluid and more normal-appearing maculas, and their vision improved. Avastin™ is also used, therefore, to treat macular edema, or swelling of the macula.

The goal of treatment is to prevent further loss of vision. Although some patients have regained vision, the medication may not restore vision that has already been lost, and may not ultimately prevent further loss of vision caused by the disease. After the pupil is dilated and the eye is numbed with anesthesia, the medication is injected into the vitreous or jelly-like substance in the back chamber of the eye. Avastin™ is administered by an injection into your eye as needed at regular intervals (about every four to six weeks); your ophthalmologist will tell you how often you will receive the injection, and for how long.

ALTERNATIVES?

You do not have to receive treatment for your condition, although without treatment, these diseases can lead to further vision loss and blindness, sometimes very quickly. Other forms of treatment are available. At present, there are two FDA-approved treatments for neovascular age-related macular degeneration:

1. Photodynamic Therapy (PDT), with a drug called Visudyne™
   
   Utilizes an innovative idea to treat CNVM’S (choroidal neovascular membranes) without damaging overlying or nearby retinal or other ocular tissues.
   
   A photosensitive dye known as Visudyne (verteporfin) is administered intravenously and allowed to perfuse the CNVM, as well as the remainder of the body. Then the ophthalmologist treats the CNVM with a red laser of a specific wavelength for about 90 seconds. The non-thermal laser light activates the Visudyne producing an active form of oxygen that both coagulates and reduces the growth of abnormal blood vessels. This, in turn, inhibits the leakage of fluid from the CNVM.
   
   Because Visudyne acts as a photosensitizer, the effect of sunlight (or ultraviolet light) on the eyes and skin may be greatly enhanced. There fore, patients should avoid exposure to sunlight for 5 days following PDT to prevent potentially severe sunburn.
   
   Patients must have realistic expectations for this form of therapy, i.e., PDT is unlikely to restore vision that has already been lost due to AMD.
   
   
   
2. Macugen™ (pegaptanib sodium injection) is another treatment therapy for wet age-related macular degeneration. It was approved by the FDA in January ’05. Macugen® targets the underlying cause of leaky blood vessels in macular degeneration.
   
   Vascular endothelial growth factor (VEGF) is a protein that has been shown to play an important role in the growth of abnormal, leaky blood vessels in the macula (where we acquire our best, acute vision) at the back of the eye. These abnormal blood vessels, called neo-vascularization, leak fluid and blood into the layers in and below the retina. This fluid creates swelling and eventually can lead to sight-damaging scar tissue in the macula.
   
   By impeding VEGF, Macugen® has been shown to inhibit new blood vessel formation and its subsequent leakage.
   
   Treatment protocol for a patient with wet macular degeneration will be in the neighborhood of 9 separate injections given 4-6 weeks apart. Macugen® is indicated in only a small amount of patients with macular degeneration. It should only be used in certain cases of wet, actively-leaking macular degeneration where it is expected that traditional treatments will not immediately help.
   
   Although both of these treatments have been proven to slow down the rate of visual loss, most people do not get back better vision.
   
   
   
3. Thermal Laser - Laser surgery is performed in ophthalmologist’s office. Before the surgery, the doctor dilates the patient’s pupil and applies drops to numb the eye. In some cases, the doctor also may numb the area behind the eye to prevent any discomfort. The lights in the office are dimmed. As the patient sits facing the laser machine, the doctor holds a special lens to the patient’s eye. The patient may see flashes of bright green or red light.
   
   The patient can leave the office once the treatment is done, but will need someone to drive them home. Because the pupils remain dilated for a few hours, the patient should bring a pair of sunglasses. For the rest of the day, the patient’s vision may be a little blurry. The eye may also hurt a bit. This is easily controlled with drugs that the doctor can suggest. The patient usually needs to make frequent follow-up visits. During each exam, the patient may have fluorescein angiography to make sure that the blood vessels are not still leaking. If the vessels continue to leak, the patient might require additional laser surgery.

Is there any other way to slow down AMD?

It has been reported that supplement of zinc and the antioxidants vitamin C, vitamin E and beta-carotene can slow the progression of wet AMD. In people with intermediate-stage disease, zinc reduced the risk of the disease progressing to the advanced stage by 11%, and the antioxidants reduced the risk by 10%. When the two were combined, the risk was reduced by 19%.

Where can I get these vitamins?

We have vitamins specifically formulated for the dry and wet forms of macular degeneration. Ask your doctor or one of the office staff for further information.

What can a person do if he or she has already lost some vision to AMD?

Normal use of the eyes will not cause further damage to vision. Even if a person has lost some sight to AMD, they should not be in the least afraid to use their eyes for reading, watching TV, and other usual activities. 

Low vision aids are available to help a patient make the most of their remaining vision. Low vision aids are special lenses or electronic systems that make images appear larger. If a patient needs low vision aids, the doctor can often prescribe them or refer the patient to a low vision specialist.

The Role of the Retina
The retina is the light-sensitive area found at the back of the eye that is critical to seeing. It can turn light, or an image, into electrical impulses, or signals to your brain. It’s your brain that works with your retinal to decide what it is that you are looking at.

The Role of the Macula
The macula is located in the center of the retina. It is the area that lets you see color and fine detail, which is critical to performing everyday activities. It’s the macula that helps you in tasks like reading or cooking. If you are reading a book, the macula allows you to see the words on each page. If you are cooking, it will help you see that the cookies are just right or are burning.

If the macula is damaged because of wet AMD, you’ll have blurred central vision. You may also notice that straight lines seem wavy.

Monitor Your Vision Regularly with an Amsler Grid

It’s very important to monitor your vision, but it’s also important to have regular eye examinations. If you notice any changes to your vision, talk to a retina specialist right away! 

What is an Amsler Grid?

The Amsler Grid is a basic test that may help determine if you have AMD. It is a grid of black lines on a white background with a dot in the middle. The grid should appear to have perfectly straight horizontal and vertical lines with a dot in the center. However, if the area around the dot appears to be wavy, it may be a sign of wet AMD. If you notice any wavy lines or blurriness at all, make an appointment with one of our retina specialists.

When doing this test, keep the following in mind:

• Keep the grid at a normal reading distance-about 14 inches away.
• Do not stare at the grid for long periods of time.
• Make sure you are looking directly at the dot at the center of the grid.
• If you normally wear glasses, do so while looking at the grid.
• Make sure you are looking at the grid with adequate lighting.
• Test each eye separately. Cover the eye that you are not using.

The Amsler Grid:

Amsler Grid  courtesy of National Eye Institute, National Institutes of Health

Additional Links
http://www.lucentis.com/lucentis/
http://www.dontlosesight.org
http://www.Genentech.com
http://www.Macugen.com

Where is there more information about Macular Degeneration?

American Academy of Ophthalmology
655 Beach Street, P.O. Box 7424
San Francisco, CA 94109-7424
415-561-8500

American Optometric Association
243 Lindbergh Boulevard
St. Louis, MO 63141
314-991-4100

Association for Macular Diseases
210 E. 64^th Street
New York, NY 10021
212-605-3719

(The) Foundation Fighting Blindness
Executive Plaza 1, Suite 800
11350 McCormick Road
Hunt Valley, MD 21031-1014
1-800-393-7634
410-785-1414

Macular Degeneration International
6700 North Oracle Road, Suite 121
Tuscon, AZ 85704
1-800-393-7634
520-797-2525

National Eye Institute
2020 Vision Place
Bethesda, MD 20892-3655
301-496-5248

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