DRY AMD (Age-Related Macular Degeneration)

WHAT IS DRY AMD

Dry AMD affects about 90 percent of all people with macular degeneration and is characterized by drusen.

Drusen are small yellow deposits that are visible to the doctor on clinical examination of the macula and are the hallmark of AMD. Most people with drusen alone do not have significant visual changes or vision loss. A minority of people with dry AMD will advance to central vision loss due to geographic atrophy, which involves the loss of pigmented cells beneath the macula (these pigmented cells normally act to support and nourish the photoreceptor cells). There is currently no treatment or cure for geographic atrophy, though multiple investigative clinical research trials are currently enrolling at Wills Eye Hospital.

Prognosis

Most people with AMD will retain good central vision and the ability to read in their lifetime, although dry AMD may also gradually progress to an advanced form with atrophy of the macula, limiting central vision.

Symptoms

Many people with mild dry AMD have little to no visual symptoms. Some people, however, will experience some side effects, including:

• Requiring more light to read
• Difficulty adjusting between dark and light conditions
• Mild blurring of vision

Occasionally, significant loss of central vision can occur as well. Vision loss associated with dry AMD is usually gradual or slow. Because AMD affects the macula, the symptoms are typically related to central vision tasks such as reading or driving. Peripheral vision is typically not affected.

Treatment

There is no treatment available yet that can either halt the progression or recover vision loss from dry AMD. However, the Age Related Eye Disease Study (AREDS), sponsored by the National Eye Institute (NEI) of the National Institutes of Health (NIH), showed that a specific formulation of antioxidant vitamins and minerals had a clinically proven benefit in reducing the risk of progression of dry AMD to more advanced stages and associated vision loss by 25%. In May of 2013, the NEI proposed a modification to the original AREDS formula based on the AREDS2 study, which was an update to the original AREDS clinical trial. The AREDS2 formula contains: 500 mg Vitamin C; 400 IU Vitamin E; 10 mg Lutein; 2 mg Zeaxanthin; 80 mg Zinc oxide; and 2 mg Copper oxide.

It is prudent to check with your primary care physician before starting this micronutrient supplement. In general, Vitamin E supplementation should not exceed 400 IU. In addition, unlike the original AREDS formula, there is no beta-carotene in the newer AREDS2 formulation (it was replaced by lutein and zeaxanthin). This is significant because some studies in the medical literature have identified increased rates of lung cancer with high levels of beta-carotene in heavy smokers.

Based on epidemiologic studies, certain lifestyle and nutritional changes may be beneficial. Based on what is known to date, the following recommendations may be made in hopes of improving the prognosis of dry AMD:

• Stop smoking. Smoking has been associated with vision loss and more advanced forms of AMD.
• Eat a diet rich in colorful vegetables and fruits. These food groups have been associated with lower rates of progression to advanced AMD and contain anti-oxidants (eg. lutein) which may slow progression of disease.
• Control blood pressure. High blood pressure is associated with more advanced AMD.
• Be physically active. People with AMD who are physically active several times a week may reduce their risk for progression to advanced AMD and vision loss.
• Consider eating food rich in Omega 3 fatty acids.  Omega 3 fatty acids are found in cold water fish such as tuna and salmon along with nuts.  Studies show that a diet with high omega 3 fatty acid intake is associated with less advanced AMD.

FOR MORE INFORMATION ON DRY AMD OR TO SEE A RETINA SPECIALIST AT WILLS EYE HOSPITAL, PLEASE CALL US AT 215-928-3444 OR FILL OUT OUR MAKE AN APPOINTMENT FORM.