Macular Degeneration

What is Macular Degeneration or Age Related Macular Degeneration?

Macular degeneration or Age-Related Macular Degeneration is caused by the deterioration of the central portion of the retina. The retina is essentially on the back part of the eye and image processing center that is responsible for transmitting images to the brain.

The images are sent through the optic nerve from the eye to the brain. The retina's central portion, known as the macula, is responsible for focusing central vision in the eye, and it controls our ability to read, work on computers, play athletics, or simply recognize familiar people. Macular degeneration is the leading cause of blindness affecting more Americans than cataracts and glaucoma combined.

The good news is that you may have some control over the risk factors. Unfortunately there are millions of Americans that are not aware that macular degeneration is an incurable eye disease and that it is the leading cause of blindness for those aged 55 and older.

Age Related Macular Degeneration (ARMD): Wet Age Related Macular Degeneration & Dry Age Related Macular Degeneration

ARMD affects millions of elderly Americans and runs the spectrum from not affecting vision at all to causing legal blindness and severe visual disability. There are two basic forms of the disease: Dry ("Nonexudative) and Wet ("exudative"). In general the Dry form does not lead to severe visual loss unless it converts to become Wet. About 90% of patients with severe visual loss have Wet ARMD. Fortunately only about 15% of ARMD patients overall have the Wet form of the disease.

While there is no treatment for Dry ARMD, taking antioxidant vitamins with zinc has been demonstrated to decrease the chance of progressing from the Dry to the Wet form. More information on the Age Related Eye Disease Study (AREDS) can be found here. Although not as extensively studied it is also believed that taking Lutein is helpful in preventing Wet ARMD. For this reason it is important to eat leafy green vegetables that contain lutein (e.g. spinach and collard greens) in addition to taking vitamin supplements. Your doctor will be able to recommend which vitamins to take and coordinate this with your primary care physician so you are taking the proper amounts of all the necessary supplemental vitamins and minerals.

Smoking increases the chance of blindness from ARMD by about 2 to 3 times compared to nonsmokers. Cessation of smoking is, therefore, probably even more important than taking supplemental nutrients. Smokers also should be aware that they should use a vitamin supplement without Betacarotene, as this is associated with a slightly higher risk of lung cancer in current and even former smokers.

Treatment of Wet Age Related Macular Degeneration:

There is no treatment for Dry Macular Degeneration yet. The only treatments that are available are indicated for Wet Macular degeneration. Your doctor will ask that you report any changes in vision (especially new onset "wavy" or "curvy" vision - called metamorphopsia) immediately. He or she will do a dilated exam in order to see the retina in the back of the eye. Certain signs such as bleeding, thickening, or yellow exudates will tell your doctor that you may have Wet ARMD. The two tests that will enable your doctor to select the proper treatment for you are Optical Coherence Tomography (OCT) and Fluorescein Angiography (FA). OCT determines if there is fluid or thickening within or even beneath the retina. The FA determines how much leakage is present and whether the leakage is affecting the fovea (the center of the macula).

Fluorescein is a dye that is injected into the arm and travels throughout the arteries and veins of the body. A special camera is used to visualize the dye in the blood vessels of the retina; if the dye leaks out of the blood vessels this is termed Wet Macular Degeneration. The yellow dye is secreted in the urine, sweat and tears. The patient's skin will also be yellow for about 8 hours. About 5% of patients will have severe nausea and vomiting for a few minutes as a result of the fluorescein; this is not a true allergy, though. Rarely patients can manifest an allergy and even have a heart attack or die from the dye.

If the leakage is localized to an area far enough from the fovea then thermal laser can be used to burn the bleeding blood vessels; although the laser produces a permanent dark spot ( a scotoma) outside the central vision it may stop the leakage altogether. Unfortunately only about 10% of patients have lesions that are amenable to laser, and even some of these patients may develop new areas of bleeding in the center weeks, months or even years after the laser.

The treatment of choice for most patients with Wet ARMD is anti-VEGF therapy. These medications are directed against the Vascular Endothelial Growth Factor (VEGF) that stimulates the growth of the rogue blood vessels. The three medications are Macugen, Avastin, and Lucentis. They all require multiple doses. The goal with the new treatments, unlike previous treatments such as thermal laser or photodynamic laser, is to improve, rather than simply stabilize, the vision. These medicines work best with early lesions, i.e. when the vision has not been severely compromised and before fibrosis and scarring sets in; once this occurs the vision will rarely improve even with therapy.

Your doctor will discuss which medication is best suited for you. The medications are administered in the office. After the eye has been numbed with topical anesthetic, and cleaned with betadine and an antibiotic drop, the needle is placed through the white part of the eye (the sclera) into the vitreous (which is in front of the retina). You may feel some pain for a few seconds as this is done. The procedure will be repeated at 4 to 6 week intervals depending upon the drug. Your doctor will decide based upon your exam, OCT and FA when the treatment interval can be lengthened or even stopped.

For further information please see www.macular.org and www.eyesight.org.

Additional Information Can be found on the website:

http://www.macular-degeneration-treatment.net