 Macular Degeneration is caused by the deterioration of the central portion of the retina, the inside back layer of the eye that records the images we see and sends them via 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, drive a car, recognize faces or colors, and see objects in fine detail.
Age related macular degeneration (AMD) is one of the most common causes of poor vision after age 60. Although the specific cause is unknown, AMD seems to be in part due to aging. While age is the most significant risk factor for developing AMD, heredity, blue eyes, high blood pressure, cardiovascular disease, and smoking have also been identified as risk factors. AMD accounts for 90 percent of new legal blindness in the US.
Dry Form
Nine out of 10 people who have AMD have the dry form, which results in thinning of the macula, the area of the retina responsible for central vision. Dry AMD takes many years to develop.
Wet Form
The wet form of AMD occurs much less frequently (one out of 10 people) but is more serious.
 The visual symptoms of Age Related Macular Degeneration involve loss of central vision. While peripheral vision is unaffected, one loses the sharp, straight-ahead vision necessary for driving, reading, recognizing faces, and generally looking at detail. Imagine being able to see a clock on the wall but being unable to make out the time or unable to read because you could not see parts of words on the page.
Promising Age Related Macular Degeneration research is being done on many fronts. In the meantime, high-intensity reading lamps, magnifiers and other low-vision aids help people with AMD make the most of remaining vision.
Aging
Approximately 10% of patients 66 to 74 years of age will have findings of macular degeneration. The prevalence increases to 30% in patients 75 to 85 years of age.
Smoking
The only environmental exposure clearly associated with macular degeneration is tobacco smoking. Not only does smoking increase the risk of macular degeneration development, current or ex-smokers cannot take vitamin supplements that have beta carotene because the risk of lung cancer increases if they do so.
Family History of Macular Degeneration
Macular degeneration appears to be hereditary in some families but not in others. Approximately one fourth of all late-stage macular degeneration appears to have a genetic basis. The lifetime risk of developing late-stage macular degeneration is 50% for people who have a relative with macular degeneration.
Other Possible Risk Factors
| • | Exposure to sunlight especially blue light. | | • | Hypertension. | | • | Cardiovascular Risk Factors (high cholesterol, obesity). | | • | Female gender. | | • | Non-hispanic Whites. | | • | Hyperopia (Farsightedness). |
 Once dry AMD reaches the advanced stage, no form of treatment can prevent vision loss. However, treatment can delay and possibly prevent intermediate Age Related Macular Degeneration from progressing to the advanced stage, in which vision loss occurs. The National Eye Institute's Age-Related Eye Disease Study (AREDS) found that taking a specific high-dose formulation of antioxidants and zinc significantly reduces the risk of advanced AMD.
Wet Age Related Macular Degeneration can be treated with laser surgery, photodynamic therapy, and injections into the eye. None of these treatments is a cure for wet AMD. Each treatment may slow the rate of vision decline or stop further vision loss, but the disease and loss of vision may progress despite treatment.
Laser Surgery
This procedure uses a laser to destroy the fragile, leaky blood vessels. A high energy beam of light is aimed directly onto the new blood vessels and destroys them, preventing further loss of vision. However, laser treatment also may destroy some surrounding healthy tissue and some vision. Only a small percentage of people with wet AMD can be treated with laser surgery.
The risk of new blood vessels developing after laser treatment is high. Repeated treatments may be necessary. In some cases, vision loss may progress despite repeated treatments.
Photodynamic Therapy
A drug called verteporfin is injected into your arm. It travels throughout the body, including the new blood vessels in your eye. The drug tends to "stick" to the surface of new blood vessels. Next, a light is shined into your eye for about 90 seconds. The light activates the drug. The activated drug destroys the new blood vessels and leads to a slower rate of vision decline. Unlike laser surgery, this drug does not destroy surrounding healthy tissue. Because the drug is activated by light, you must avoid exposing your skin or eyes to direct sunlight or bright indoor light for five days after treatment. Photodynamic therapy is relatively painless. It takes about 20 minutes and can be performed in the office.
Photodynamic therapy slows the rate of vision loss. It does not stop vision loss or restore vision in eyes already damaged by advanced Age Related Macular Degeneration. Treatment results often are temporary. You may need to be treated again.
Injections
Wet Age Related Macular Degeneration can now be treated with a new drug that is injected into the eye (anti-VEGF therapy). Abnormally high levels of a specific growth factor occur in eyes with Wet AMD and promote the growth of abnormal new blood vessels. This drug treatment blocks the effects of the growth factor.
You will need multiple injections, usually given about six weeks apart. The eye is numbed before each injection. After the injection, you will remain in the office for a while and your eye will be monitored. As with photodynamic therapy, the main benefit for patients treated with the drug is to slow vision loss from AMD.
Early detection is the best defense against vision loss. There are several tests that need to be done to determine the proper diagnosis of macular generation as outlined below.
Visual Acuity Test
This eye chart test measures how well you see at various distances.
Dilated Eye Exam
Drops are placed in your eyes to widen, or dilate, the pupils. A special magnifying lens is used to examine your retina and optic nerve for signs of Age Related Macular Degeneration and other eye problems. After the exam, your close-up vision may remain blurred for several hours.
Tonometry
An instrument measures the pressure inside the eye. Numbing drops may be applied to your eye for this test.
Other Tests
We may do other tests to learn more about the structure and health of your eye.
During an eye exam, you may be asked to look at an Amsler grid. The pattern of the grid resembles a checkerboard. You will cover one eye and stare at a black dot in the center of the grid. While staring at the dot, you may notice that the straight lines in the pattern appear wavy. You may notice that some of the lines are missing. These may be signs of AMD.
If Dr. Benjamin believes you need treatment for wet Age Related Macular Degeneration, he may suggest a fluorescein angiogram. In this test, a special dye is injected into your arm. Pictures are taken as the dye passes through the blood vessels in your retina. The test allows your eye care professional to identify any leaking blood vessels and recommend treatment.
What can I do that might reduce my risk of developing macular degeneration?
| • | Eat large quantities of dark green leafy vegetables rich in carotenoids, the yellowish pigments that include precursors of Vitamin A. Spinach and collard greens are possibly the most beneficial vegetables in this respect. | | • | Protect your eyes from potentially harmful ultra-violet (UV) light and blue light. | | • | Antioxidant vitamin and zinc supplements may help. | | • | Don't smoke. | | • | Eat a low-fat diet. Avoid junk food. | | • | Exercise regularly. |
Prevention
 The results of an age-related eye disease study (AREDS) conducted by the National Eye Institute to determine the effects of vitamins and minerals on the progression of Macular Degeneration are listed below. Patients with Age Related Macular Degeneration or vision loss due to Age Related Macular Degeneration in one eye and without contraindications such as smoking should consider taking the following vitamin supplements:
| • Vitamin E | 400 I.U. | | • Vitamin C | 500 mg | | • Beta Carotene | 0.15 mg | | • Zinc Oxide | 80 mg | | • Copper (such as cupric oxide) | 2 mg. |
Early detection and treatment is the best defense against vision loss.
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