Copyright Nucleus Medical Media, Inc.
The retina is the tissue that lines the back of the eye and sends visual signals to the brain. The macula is the center part of the retina. Macular degeneration is a chronic and progressive disorder that affects the macula and reduces the ability to see.
It causes a gradual loss of sharp, central vision, and is the leading cause of blindness in older adults in the United States.
It affects about 10 million Americans each year, more than glaucoma and cataracts combined.1
The frequency of macular degeneration increases with age, with the majority of affected people over the age of 75. In rare cases, it can occur in younger people. Adult macular degeneration (AMD) is the most common form of macular degeneration.
There are 3 stages of AMD, depending on the presence and size of drusen (yellow deposits beneath the retina), pigment changes in the retina, the amount of macular damage, and the severity of visual changes:
Stage 1: Medium-sized drusen (about the width of an average human hair) are present, but no macular changes or vision loss.
Stage 2: Large drusen are present with pigment changes in one or both retinas, and some vision loss, but no macular changes or other symptoms.
Stage 3: There is evidence of more severe vision loss and macular changes.
- Dry (geographic) AMD is the most common and involves macular thinning due to a slow breakdown of cells in the macula.
- Wet (neovascular) AMD also includes abnormal blood vessels that grow under the retina and macula. This can result in macular damage from pressure, bleeding, and fluid leakage.
Symptoms of Macular Degeneration
In some people, macular degeneration advances so slowly that it has little effect on their vision. In others, the disease progresses faster and may lead to vision loss. Sometimes only one eye is affected, while the other eye remains free of problems for many years. People with dry macular degeneration in one eye often do not notice any changes in their vision. With one eye seeing clearly, they can still drive, read, and see fine details. Some people may notice changes in their vision only if macular degeneration affects both of their eyes. Both dry and wet macular degeneration cause no pain.
Symptoms of macular degeneration include:
- Blurred Vision: This is an early warning sign. You also may need more light for reading and other detailed tasks.
- Difficulty Seeing Details In Front Of You: You may have a difficult time seeing faces or words in a book.
- Blind Spot: A small, growing blind spot appears in the middle of your field of vision. This spot occurs because a group of cells in the macula have stopped working properly. Over time, the blind spot may get bigger and darker, taking up more of your central vision.
- Crooked Lines: An early symptom of wet macular degeneration is seeing straight lines that appear crooked or wavy. This happens because the newly formed blood vessels leak fluid under the macula. The fluid raises the macula from its normal place at the back of the eye and distorts vision.
- Lighting: Images appear more gray in color and colors are not as bright
Contact your ophthalmologist immediately for an eye exam if you notice:
- Visual distortions
- Sudden decrease in central vision
- A central blind spot
- Any other visual problems
Diagnosing Macular Degeneration
Your doctor will ask about your symptoms and medical history, and a physical exam will be done. Your doctor may suspect adult macular degeneration if you are over the age of 50 and have changes in your central vision. You likely will be referred to an ophthalmologist, who will look for additional signs of macular degeneration.
Eye evaluations for macular degeneration include:
- Visual Acuity Test: This eye chart test measures how well you see at different distances.
- Pupil Dilation: Eye drops are placed in your eyes to dilate, or enlarge, your pupils so that the doctor can view the back of your eye. The presence of drusen, tiny yellow deposits in the retina, can indicate that the eye is at risk for developing AMD. The doctor also will look for any pigment changes, macular damage, or new blood vessels. After the examination, your vision may remain blurred for several hours due to the dilating drops.
- Amsler Grid: You may be asked to view an Amsler grid, a pattern that looks like a checkerboard, to test for changes in your central vision. You will be asked to 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 or that some of the lines are missing, indicating loss of central vision. These may be signs of macular degeneration.
- Fluorescein Angiography: If your eye care professional suspects you have late neovascular macular degeneration, you may need to have a test called fluorescein angiography. In this test, a special dye is injected intravenously (IV) into the bloodstream. Pictures are taken as the dye passes through the blood vessels in the retina. The photos help your eye care professional evaluate leaking blood vessels to determine how best to treat them.
Risk Factors for Developing Macular Degeneration
A risk factor is something that increases your likelihood of getting a disease or condition. Risk factors for macular degeneration include:
- Age: Adult macular degeneration is more common in people over 50, and the risk increases with advancing age.
- Gender: Adult macular degeneration is more common in women.
- Race: According to the Third National Health and Nutrition Examination Survey2, adult macular degeneration is more common in people who are Caucasian.
- Family History: Genetic factors appear to be very common in early-onset types of macular degeneration. Specific genetic causes for adult macular degeneration are unknown, but a family history of the condition is thought to increase your risk of developing it.
- Other factors that may increase your risk of macular degeneration include:
- Cataract surgery
- High blood pressure
- Heavy alcohol use
- High cholesterol
- Exposure to excessive sunlight
- Taking certain drugs — Ask your doctor if your medications can increase your risk of macular degeneration.
Treating Maculation Degeneration
The treatment recommended for your macular degeneration will depend on its classification and type. The goal of treatment is to delay disease progression, and reduce visual and functional impairment. There are no oral medications for macular degeneration, but treatment may involve:
If you have been diagnosed with macular degeneration, you can make some changes that will help you manage your environment with low vision. You can make your home a safer place by taking these steps:
- Brighten your space with overhead and under-cabinet lighting. Experiment with different types of bulbs to see which work best for you.
- Reduce glare with curtains and blinds.
- Keep an open room flow by rearranging furniture that may hinder movement.
- Use contrasting colors in the bathroom so it is easier to see large items like the bathtub, toilet, and sink.
- If you have area rugs, make sure they are taped or tacked down to avoid falls.
- In stairwells use bright lights and identify the top and bottom steps with different colors.
- Install handrails in bathrooms and in stairwells.
Daily life with macular degeneration may be difficult. Follow these suggestions to help make your daily tasks easier:
- When reading or using a computer, use large text options or extra spacing between letters when you can. If you still have difficulty, try audio books.
- Organize your household items and keep them in the same place all the time so that they are easier to find.
- Try using large stickers on your stove or thermostat so they are easier to use.
- Use magnifiers or telescopes. Telescopic lenses are mounted inside the lenses in your glasses. They work by magnifying, much like a telescope or binoculars. With magnification, tasks such as needlework, movie watching, or other daily tasks may be more manageable.
For most people, driving defines their independence. If your low vision is causing problems when you drive, you may have to make some adjustments. It does not mean you have to turn in your keys permanently. Take these steps:
- Plan your driving for daylight hours. Avoid driving at dawn and dusk, or after dark.
- Monitor weather and traffic conditions.
- Ask your family or friends for help when you need it.
- Consider taking a driver's education course to improve driving skills.
- In some states, telescopic lenses are legal for driving. If you are unsure, contact your state motor vehicle department.
In some cases, certain lifestyle changes may even slow the progression of macular degeneration. These include:
- Antioxidant vitamins and zinc may reduce vision loss caused by certain forms of AMD. Talk to your doctor or a registered dietitian about vitamin and mineral supplements.
- Smoking can be harmful to the eye, just as it is to the rest of the body. If you smoke, talk with your doctor about ways to quit.
Surgical procedures can help the symptoms of certain kinds of AMD. These include:
Laser photocoagulation is an outpatient procedure used in some cases of wet macular degeneration. When blood vessels under the macula multiply in wet macular degeneration they leak, causing damage and death to the cells of the macula. Photocoagulation involves aiming a strong laser light beam onto the new blood vessels to destroy them. It is not a cure for macular degeneration, but helps prevent further vision loss. You may need additional laser treatments to manage macular degeneration and prevent further vision loss.
Photodynamic therapy is a type of outpatient laser procedure used to treat wet macular degeneration. It involves using a low-powered laser in conjunction with a light-sensitive dye. The dye is injected into a vein in your arm and circulates through your body. As the dye moves through the blood vessels of your eye, it collects in the abnormal blood vessels. A low-intensity laser is aimed at the blood vessels. The dye absorbs the laser energy and destroys the blood vessels.
Anti-VEGF injections can be used for all forms of wet macular degeneration. The medication is injected directly into the eye after you are given topical numbing medication. It blocks a signal that causes the abnormal blood vessels to grow and leak. These injections are usually performed by a retina specialist and are given about every 6 weeks. Although not a cure, these injections can help slow progression and preserve the vision you currently have.
Surgical removal of blood and abnormal blood vessels below the macula have been attempted, but have not been very successful. Researchers are investigating this and other forms of surgical intervention for macular degeneration.
Implantable Miniature Telescope
The implantable miniature telescope (IMT) is for people who have late-stage, age-related macular degeneration. During this procedure, a tiny, pea-sized telescope is surgically implanted in one eye. This telescope, which provides double the magnification, is designed to improve the person's vision by magnifying the image on the healthy portion of the retina.
Other Treatments and Rehabilitation
In addition to dietary and other behavior modifications, management of macular degeneration involves psychosocial treatments and vision rehabilitation. You may have difficulty adjusting to decreased vision at first. Feeling anxious, depressed, angry, or lonely is common and, as with any loss, you may experience grief.
This can be stressful not only for you, but for your loved ones. Individual, couple, or family therapy can help you learn how to cope more effectively and get the support you need. AMD support groups also can help you and your family share feelings, frustrations, and solutions to certain challenges. It is important that you develop and maintain a strong support system to prevent isolation and depression.
In addition to emotional support and comfort, you may need physical and financial assistance. Make sure that you have family members, friends, and other supporters to help you with tasks like cooking, paying bills, taking your medications, and transportation to medical appointments and social events.
You may want to find a social worker to help you and your family access community, state, and federal resources for the visually impaired. Your eye care professional can help you register with your state’s Commission for the Blind, if you qualify.
You need to maximize your remaining vision so that you can continue with many of your daily activities. A "low-vision" specialist can help assess your remaining vision, recommend optical aids and devices, and provide training in using these aids. Low-vision devices include:
- Adjustable lamps
- High-powered reading glasses
- Telescope-mounted lenses
- Protective filters and sun lenses
- Special bold-lined paper
- Aids for check-writing and addressing envelopes
- Reading stands
- Colored filters to enhance contrast
- Large-print publications
- Dials with large lettering for televisions and stoves
- Voice-activated devices
- Special computerized devices