What is the Macula?

There are two parts to the retina - the peripheral retina and the macula (the fovea is the very center of the macula). The macula is the small central zone of the retina, located next to the optic nerve. The peripheral retina allows to notice things "off to the side", while the macula allows us to see things straignt ahead. It allows us to recognize faces, read fine print, see small detail, thread a needle, etc...

Who Gets Macular Degeneration?

Although there are some unusual forms of macular degeneration that begin early in life, it is something that is most commonly associated with aging. Most patients with macular degeneration will develop symptoms or findings after age 50. Risk factors for macular degeneration included the following:

• hyperopia or farsightedness
• family history
• smoking
• fair skin, lighter colored eyes.

Three of the four risk factors you are born with. To eliminate the one risk factor you have control over, anyone who is a smoker should

What is Macular Degeneration?

As people age, they can sometimes develop spots in their macular called drusen. A few drusen in the macular usually does not affect the vision. If more drusen appear in the macula, the vision may become blurred. Fortunately, most patiens with drusen do not develop serious loss of vision. Only a few of these patients will develop severe macular degeneration with more significant loss of vision.

Will I go blind from Macular Degeneration?

When macular degeneration causes loss of vision, it usually starts with one eye. If the other eye remains unaffected, you should still have good vision in that eye. If severe macular degeneration is present is both eyes, there can be loss of central vision if both eyes. However, the peripheral vision is usually unchanged. By learning to look at things "off center", most people can still see well enough to care for themselves and do things that do not required detailed central vision.

What are the symptoms of Macular Degeneration?

When macular degeneration affects the vision, you may notice blurred or distorted central vision at distance or when reading.

Types of Macular Degeneration

Macular degeneration is typically classified into one of two categories: dry or wet. During your eye exam, your doctor will be able to determine which type you have.

Dry Macular Degeneration

The dry form is more common and is caused by the presence of drusen and/or thinning of the macula (central retina). This condition typically causes a slowly progressive loss of the central vision. Currently, there is no medical or surgical treatment for dry macular degeneration. Management of this disease consists of the following:

• Low vision aids to maximize vision. You may be referred to an optometrist who specializes in this field. click here for more information about dealing with low vision

• Monitoring your vision with an Amsler Grid. A change is the appearance of the grid may by a sign that the dry form is converting to the wet form. Any sudden changes in the way the grid looks (missing lines, wavy or distorted lines) should be reported to your eye doctor right away.

• Vitamin and Mineral supplements. A recent study referred to as the AREDS has suggested that taking a combination of vitamins and minerals may prevent vision loss. These nutrients are available in Ocuvite Preservision, which can be purchased over-the counter at the pharmacy or drugstore. To learn more about this, click here to learn more about Nutritional Supplements and Macular Degeneration. If you are a current or former smoker, you should consult your eye doctor before taking these vitamins.

Wet Macular Degeneration

The wet form of macular degeneration is caused by abnormal blood vessels that grow underneath the macula. Blood or fluid may leak from these vessels and accumulate under the retina, further damaging the macula or central retina. When this occurs, the vision can suddenly become more blurry or distorted. As such, it is important to monitor your vision on a regular basis with the assistance of an Amsler Grid to ensure early detection of this event. Early detection is often more amenable to treatment, although in many causes, wet macular degeneration is not treatable. If your doctor determines it is treatable, treatment consist of the following:

• Laser treatment. A laser beam can be used to destroy the abnormal blood vessels. This procedure is done in your doctor’s office in an outpatient setting.
• Photodynamic Therapy. Light activated drugs are used to destroy the abnormal blood vessels. To learn more about this, you can go to www.visudyne.com or see below.

Your doctor may order a Fluorescein Angiogram to identify the precise location of the abnormal blood vessels.

What effect will the laser treatment have on my vision?

When the laser destroys the abnormal blood vessels, a scar forms in the retina that can create a permanent blind spot in the vision. As such, the vision will usually not improve after treatment and may in fact, seem slightly worse because of the blind spot. It is important to understand that a portion of the macular may be “sacrificed” by the treatment in order to preserve the surrounding areas. Studies have shown that those have laser treatment usually lose less vision in the long run than those that do not.

Is wet macular degeneration always treated with laser?

If a large amount of blood has leaked out from the abnormal blood vessels, this condition may not be amenable to laser treatment. In some instances, you doctor may feel that laser treatment is best not done.

What is Photodynamic Therapy?

Photodynamic therapy (PDT)--an outpatient procedure involving the use of a special light-activated drug--may be used to treat some patients with the wet form of AMD with fewer visual side effects than other treatments. The benefit of PDT is that it inhibits abnormal blood vessel leakage associated with wet macular degeneration, limiting damage to the overlying retina.

In PDT, the inactive form of the drug is usually injected into a vein in the arm, where it travels to and accumulates in abnormal blood vessels under the center of the macula. A special low-intensity laser light targeted at the retina activates the drug only in the affected area, damaging the abnormal blood vessels under the retina and leaving normal blood vessels intact.

Patients who are treated with PDT will become temporarily sensitive to bright light (photosensitive). Care should be taken to avoid exposure of skin or eyes to direct sunlight or bright indoor light for several days.

PDT therapy is not effective for treatment of the dry form of AMD, caused by aging and thinning of the tissues of the macula. While photodynamic therapy may preserve vision for many people, PDT may not stop vision loss in all patients. The abnormal blood vessels may regrow or begin to leak again. Every three months, a repeat examination including a fluorescein angiogram (a dye test) is required. Multiple PDT treatments may be necessary.