ST. JOHNSBURY OFFICE

(802) 748-8126 - fax:(802) 748-2208

LITTLETON OFFICE

(603) 444-2484 - fax:(603) 444-1672

Print

Macular Degeneration



WHAT IS AGE-RELATED MACULAR DEGENERATION? (AMD)

Macular Degeneration, also known as AMD and ARMD (for age related macular degeneration), is an eye disease that is a leading cause of visual loss in older adults.  AMD affects the macula, the region of the retina that is responsible for central vision.

As we age, the macula can weaken and its structure can begin to undergo degenerative changes leading to an inability to see objects clearly.  In some people, AMD advances so slowly that vision loss does not occur for a long time.  In others, it can progress fast leading to vision loss in one or both eyes.  Macular degeneration does not cause complete blindness since it does not affect the side or peripheral vision.
 

Macular Degeneration

WHAT IS THE DIFFERENCE BETWEEN DRY AND WET MACULAR DEGENERATION?

Macular degeneration is often grouped into two categories:

  • Dry (Atrophic) Macular Degeneration
  • Wet (Exudative) Macular Degeneration

The dry form is more common and symptoms include a loss of retinal pigment and deposit of material in the tissues underlying the macula.  These changes can lead to decreased or distorted vision, but the progression of dry macular degeneration is not typically rapid.  When the disease progresses, changes in the blood vessels underlying the retina can cause bleeding or leakage and this is referred to as “wet” component of wet macular degeneration.

Back to top

WHAT ARE THE SYMPTOMS OF MACULAR DEGENERATION?

The symptoms of macular degeneration include:

  • words appearing blurry on a printed page
  • dark or empty area appearing in the center of vision
  • straight lines looking curved or distorted.

HOW IS MACULAR DEGENERATION DIAGNOSED?

Often, your doctor will detect early signs of AMD before you experience symptoms.  This is accomplished through an examination of the macula with a specialized instrument that gives the doctor a magnified view of the tissue.

If the wet form is suspected, additional testing may be indicated.  Your doctor may use a computerized imaging system called OCT (optical coherence tomography) to take cross sectional images of the retina to look for fluid and/or abnormal blood vessels.  Fluorescein angiography may also be needed where a specialized dye is injected into a vein and a series of photographs are taken of the macula.

Patients with dry macular degeneration are also encouraged to self-monitor their vision and to look for early signs of the wet form of the disease with the use of an amsler grid.  The grid is held at reading distance from the eye.  Cover each eye in turn and look at the central spot with the uncovered eye.  Normally the grid would appear as straight lines.  But if your eyes have changed from AMD, the lines may be distorted or blank spaces where the lines are not visible may be present.

WHAT CAUSES MACULAR DEGENERATION?

The exact causes of age-related macular degeneration are still unknown.  The dry form of AMD may result from the aging and thinning of macular tissues, depositing of pigment in the macula, or a combination of the two processes.  With wet AMD, new blood vessels grow beneath the retina and leak blood and fluid.  This leakage causes retinal cells to die and creates blind spots in the central vision.

WHAT ARE THE RISK FACTORS OF MACULAR DEGENERATION?

  • AGE: The most common factor is age. As we get older, the risk of getting AMD greatly increases.  At age 50 the risk is estimated to be 2%. The risk increased to 30% at 75
  • SMOKING: Smoking can double the risk for developing this disease.
  • FAMILY HISTORY: Those with immediate family members may be at increased risk.  However, this factor is dependent upon inheriting certain genes or genetic factors from relatives.
  • HIGH BLOOD PRESSURE: Poor blood circulation due to hypertension and other vascular diseases may increase the risk of getting this disorder.
  • OBESITY: Being overweight increases the risk of developing both the dry and wet form of the disease.
  • DIET: Inadequate intake of antioxidants, consumption of alcohol, saturated fats and cholesterol can create free radicals that can harm the macula.
  • GENDER: Women may be at greater risk of developing AMD than men.  This might be attributed to lower levels of estrogen in postmenopausal women.
  • RACE: AMD is the leading cause of blindness in aging Caucasian Americans.  The disease is rare in other races.  The cause is unknown, but thought to be related to the amount of pigment in the macula since light colored eyes also appear to be at a greater risk.
  • SUN EXPOSURE: Significant cumulative light exposure may increase the risk of this disease.

Back to top

IS THERE A TREATMENT FOR MACULAR DEGENERATION?

Although there is not a cure for macular degeneration, there are treatments available that may be able to delay its progression or improve your vision.  Some of these treatments include:

  • Anti-VEGF injections:  Medications are injected into the eye that blocks the hormone that contributes to the growth of abnormal blood vessels.  This can slow vision loss for people with wet type AMD.
  • Vitamins and Minerals: Dry macular degeneration can be treated under certain circumstances with a high-potency vitamin and antioxidant supplement.
  • Laser Treatments: Laser photocoagulation can help wet AMD patients by destroying or sealing new blood vessels to prevent leakage.  This therapy works best if the abnormal vessels are not close to the center of the macula.
  • Healthy Diet: Living and maintaining a healthy lifestyle can lower your risk of vision loss, especially by not smoking and not consuming large amounts of alcohol over time.  Adding fish oils and leafy greens to your diet can also help.

 

 

Back to top