Age related macular degeneration is the leading cause of vision loss in people 50 years and older in the United States. It involves damage to the macula, a small but very important area of the retina responsible for your central vision. The macula allows you to see fine details clearly. Whenever you read, drive or perform any activity that requires seeing precise details, you are using your macula. A person with AMD often loses the ability to perceive fine details both up close and at a distance. This loss of vision affects only your central vision, while your peripheral vision usually remains normal.
Everyone with AMD starts out with the “dry” form, and it is always in both eyes. The “dry” form is characterized by collections of waste products beneath the retina and the slow deterioration of the cells responsible for sight in those areas. The vision change from “dry” macular degeneration can be very mild or very severe, and can be different in each eye.
While 90% of those with AMD have only “dry” AMD, the remaining 10% have an additional condition called exudative or “wet” AMD, that occurs on top of the “dry” form. Wet AMD occurs when abnormal blood vessels grow underneath the retina. These unhealthy vessels leak blood and fluid, which can scar the macula. For patients with wet AMD, vision loss may be rapid and severe.
Although macular degeneration reduces vision in the central part of the retina, it usually does not affect the peripheral vision. In some cases, it may not affect your vision much at all. In other cases, vision loss may be more rapid and severe. It very rarely causes total blindness. In its end stage, worst case condition patients have difficulty with fine visual tasks such as reading, and driving a car. Recognizing faces can be difficult. It is important to note that the vast majority of patients with end stage macular degeneration can still lead productive, independent lives.
Causes of macular degeneration:
Many people develop macular degeneration as part of the body’s natural aging process. There are different kinds of macular problems, but the most common is age-related macular degeneration (AMD or ARMD).
The human body constantly reacts with the oxygen in the environment. Over time, as a result of this activity, our bodies produce molecules called free radicals. These free radicals affect cells and can damage them. This process – called oxidative stress – is thought to play a major role in the development of AMD. Many people (approximately 33% of Caucasians) have genetic changes that make them prone to this type of damage.
Risk factors for AMD include:
- Cigarette smoking
- Genetic predisposition or family history
- Being over the age of 50 years old
- Abnormal cholesterol levels
- Deposits under the macula, called drusen
Types of Macular Degeneration
Dry Macular Degeneration:
Ninety percent of people with AMD have only the dry form of the condition. All AMD patients have the dry form, and it is always in both eyes, though often to different degrees. This form is caused by damage (oxidative stress) and results in the thinning of the macular tissue. Vision loss tends to be gradual. The only effective treatment is vitamin supplementation to slow the progression of the disease in high risk patients.
Wet Macular Degeneration:
Ten percent of people with AMD develop the wet form of the condition. It can occur in one or both eyes. Many of these people develop significant vision loss without treatment. Wet AMD occurs when abnormal blood vessels form underneath the retina. These new blood vessels leak fluid or blood and blur central vision. Vision loss can be rapid, severe and permanent.
Symptoms of macular degeneration:
Different symptoms may appear in different people. For some, symptoms in the early stages of macular degeneration are barely noticed, particularly if one eye loses vision while the other eye continues to see well. If both eyes are severely affected, however, you will likely notice the loss of central vision. Distortion of vision may cause the words on a page to appear blurred, dark or empty areas may appear in the center of vision, and straight lines may look distorted or wavy.
Amsler grid monitoring is the most effective way to monitor your vision for signs of progression. Vision should be monitored daily, and each eye should be checked separately. Any change in the grid should be cause for alarm. If you notice changes, you should contact Dr Comaratta’s office for evaluation within 2-3 days.
The doctor can help detect the early stages of AMD during a medical eye examination that will include a simple vision test, an exam of your macula with high definition scans of the retina, and evaluation under the microscope.
Dry Macular Degeneration
Treatment of dry macular degeneration is limited to vitamin supplementation (AREDS2 formula) to prevent progression of the disease in patients with moderate to high risk characteristics. The Age Related Eye Disease Studies (from which the AREDS formula gets its name) found that vitamins reduce the rate of progression of AMD from around 30% over the course of five years to about 20%. The currently recommended formula is the AREDS2 formula, from the latest version of the study.
Wet Macular Degeneration
Treatment for wet macular degeneration has improved dramatically over the last 15 years. The key to effective treatment is early detection, especially with Amsler grid monitoring on a daily basis and regular eye exams. Anyone who has dry macular degeneration should be utilizing an Amsler grid to test both eyes. Any change in your vision or distortion on the grid is a cause for concern. You should contact Dr. Comaratta and arrange to be seen within 2-3 days of the onset of a change.
The most common treatment for wet AMD involves injecting a drug into the eye that stops blood vessel growth and bleeding. These drugs, called VEGF blockers (anti-VEGF) target a specific chemical in the body that causes abnormal blood vessels to grow under the retina. These medications have revolutionized the treatment of wet AMD. Early intervention is critical for effective treatment with these medications.
With early detection and prompt treatment, wet macular degeneration can be effectively controlled and excellent vision can be maintained. Wet AMD is rarely cured and requires vigilance and frequent follow up with your retina specialist. The goal of anti-VEGF treatment is to maintain the best possible vision with the least number of treatments. Your treatment will be tailored specifically to you based upon your treatment response.
Most exciting is the continued evolution in our treatment options. If one medication is not effective, we have two additional options to utilize. The majority of patients respond to at least one of the medications, and the vast majority of patients (90%) respond equally well to all three.
Often, patients have anxiety about the injection itself. With appropriate topical anesthesia, the injection itself is painless. The vast majority of patients are not even aware that the injection has taken place. There is occasionally some discomfort after the injection due to the sterilizing solution placed in the eye to prevent infection. The doctor recommends aggressive lubrication with artificial tears or ointment to ease any discomfort following the procedure. Patients are encouraged to return to normal activity as soon as they feel comfortable.
Low Vision Therapy
Once your condition is stabilized, you may be a candidate for low vision aids. In those patients who are having difficulty with their central vision, these aids can greatly enhance your visual functioning. Our staff can make the appropriate referral to a low vision expert upon the doctor’s recommendation.