What is Macular Degeneration?
Age related macular degeneration is the leading cause of registered blindness in people over 50 years worldwide, yet awareness remains low.
Approximately 25-30 million people are affected by some form of Age Related Macular Degeneration (ARMD).
Facts about AMRD :
What is Age Related Macular Degeneration?
Age related macular degeneration (AMRD) is a degenerative retinal eye disease that causes progressive loss of central vision, leaving only peripheral, or side vision intact.
ARMD affects the macula (see diagram), the central part of the retina responsible for clear, central vision needed for daily activities like reading or driving.
Clinical Definition :
Central Vision loss from ARMD is caused by the degeneration of light-sensing cells in the macula called photoreceptors. The macula is the central portion of the retina responsible for perceiving fine visual detail. As these photoreceptors begin to degenerate, so does the individual’s central vision. The extend of vision loss varies widely and is related to the type of ARMD, its severity and other individual characteristics.
What are Two Types of ARMD?
- Dry ARMD
The more common and milder form of ARMD, accounts for 85% to 90% of all cases.
Dry ARMD results in varying forms of sight loss and may or may not eventually develop into the wet form.
One key identifier for AMRD is the collection of small, round, white-yellow, fatty deposits called drusen in the central part of retina. Drusen accumulate in the Retinal Pigment Epithelum (RPE) tissue beneath the macula.
- Wet ARMD
The wet form of ARMD accounts for only 10-15 percent of all ARMD, however the chance for severe sight loss is much greater. It is responsible for 90 percent of severe vision loss associated with ARMD. Approximately 70% of those with wet ARMD become registerably blind within two years of diagnosis. Wet ARMD is caused by the growth of abnormal
Blood vessels, or choroidal neovascularisation (CNV), under the central part of the retina, the macula.
These abnormal vessels leak fluid and blood into the tissue at the back of the eye, causing a blister to form in the retina. This progression eventually leads to scar tissue, distortion and a loss of central vision.
What are the symptoms?
- Slow / rapid progression of loss of central vision. Peripheral vision usually remains normal.
- Difficulty in distinguishing colour.
- Edges / lines may appear wavy and faces may appear blurred.
- Advanced cases of ARMD may see dark or empty spaces that block the central vision.
Does age related macular Degeneration cause blindness?
While ARMD rarely causes Total blindness, the loss of central Vision may make everyday activities extremely difficult. Visual deterioration associated with wet ARMD is generally severe and can be rapid.
Vision Loss with dry ARMD is usually gradual.
A patient may begin to notice blank areas in central visual field. Over time, dry ARMD can cause a large loss of detail vision; however, vision loss is generally not as severe compared to the wet form.
In either form of ARMD, once retinal tissue is damaged, lost vision cannot be regained.
How do I know if I have Macular Degeneration?
A chart called the Amsler Grid may be used in some cases to highlight visual distortions symptomatic of ARMD.
Of course, only a professional eye examination by an eye care specialist can properly diagnose ARMD. If wet ARMD is suspected, pictures of the retina are taken after injecting a dye in the vein of the arm. This procedure is known as fundus fluorescein angiography.
What causes AMRD ?
It is generally unknown as to what causes ARMD. The only clinically proven risk factor is smoking. Several studies have identified possible additional risk factors:
- A recent study identified a hereditary link, and determined that first-degree relatives of patients with wet ARMD may have three times the risk of developing the disorder. We recommend that patients who have blood relatives with ARMD have their eyes checked every two years.
- Patients with dry ARMD on anti-hypertensive drug therapy coupled with high serum cholesterol levels and low serum carotenoids are at a greater risk for developing wet ARMD.
- Sun exposure.
- Light skin or eye color.
- Postmenopausal women who do not undergo estrogen therapy are also at a greater risk of developing ARMD.
- In general, the incidence of ARMD is most prevalent in white women over 60.
How many people are affected by ARMD?
Approximately 500,000 new cases of wet ARMD are diagnosed annually worldwide and some form of ARMD affects approximately 25-30 million individuals. This number is expected to triple over the next 25 years.
If ARMD is such a serious disease, why are people not aware of it?
Even with the severity of ARMD, global awareness of the disease remains minimal. In a recent survey commissioned by the ARMD Alliance International, only 2% of adults surveyed think the leading cause of severe sight loss among adults of age 50 or older is age related macular degeneration. 82% of adults surveyed were unfamiliar with ARMD.
Is ARMD treatable?
There is currently no treatment for dry ARMD.
There are two clinically proven treatments for wet ARMD :
The first treatment is laser Photocoagulation, a procedure involving the application of a hot laser to sea and halt or slow the progression of abnormal blood vessels.
However, this procedure may produce a blind spot (scotoma) in the vision.
Certain cases of wet ARMD may also be treated using conventional diode laser by a method known asTranspupillaryThermo Therapy (TTT). Here laser beam is used to produce heat energy which destroys the membrane in wet AMRD.
The second one is Photodynamic Therapy, a Treatment that uses non- thermal (or cold) laser.
An Intravenous light sensitive drug is used along with laser to halt or slow the progression of abnormal retinal blood vessels. This treatment does not leave a blind spot in the vision.
While many Photodynamic therapies are in clinical trials, verteporfin (Visudyne TM) has recently received regulatory approval in over 40 countries covering Europe, North and South America as well as the Asia Pacific Region. Other therapies are still under clinical investigation.
Early diagnosis is key to effective treatment because once vision is lost due to the growth of abnormal blood vessels, it cannot be reclaimed
Can surgery help care macular degeneration?
Surgery to remove the scar produced by macular degeneration has been successful in younger patients, but less successful in older patients. If the degeneration is associated with leaking blood vessels in the center of the macula, and vision is worse than 20/70, laser surgery, called photocoagulation, is recommended. This will not improve vision but generally reduces further vision loss. Retinal transplantation is a new experimental approach to macular degeneration, but will require at least 3 – 5 years of clinical research to determine its safety and effectiveness.
How can I avoid losing vision to ARMD?
There are steps to take to minimize risk factors and decrease the chances of developing ARMD.
- Make Regular Eye Examination : Early detection of ARMD through regular medical eye examination/tests (every year) is crucial so that options for treatment, rehabilitation and support services can be administered early enough to make the greatest impact.
- Quit Smoking : Smokers are at a greater risk of developing macular degeneration than non-smokers.
- Control High Blood Pressure : A link has been found between high blood pressure and ARMD.
- Protect Your Eyes from Ultraviolet (UV) Light : UV may also damage your retina. This increases your chances of developing macular degeneration and may also speed up the development of ARMD. Wear a hat or visor when you are outside, even on cloudy days, and buy sunglasses that block out 99-100% of all ultraviolet rays.
- Eat a Healthy Diet : A diet rich in fruits and vegetables and low in saturated fat seems to help people with ARMD. Some studies have found dark green leafy vegetables beneficial in lowering the risk of wet ARMD.
The role of vitamins, minerals, and antioxidants in the prevention of macular degeneration has been a source of controversy and conflicting information; high serum levels of vitamins E, A, and C, as well as zinc, may be beneficial, but currently their efficacy is unproven.
- Exercise Regularly : Exercise contributes to both eye health and overall well being.
What is the rehabilitation option available for ARMD patients ?
Although there is no cure for ARMD, hope does exist. Those diagnosed with ARMD may maintain independent lifestyles through treatment and rehabilitation, options are available such as low vision aids (e.g. strong reading or telescopic lenses, etc.), support services that help activities of daily living, These options should be discussed with an eye care specialist.
Conversation between ARMD patient and doctor
An ARMD patient’s ability to ask the right questions and receive accurate information and options at the time of diagnosis is crucial. This way, together the ARMD patient and the eye care provider can address appropriate options for treatment, rehabilitation and support services in order to maintain the highest possible quality of life for the patient.
- How did I get this disease – What are the risk factors?
Answer: The cause of ARMD is still unknown, and the only clinically proven risk factor is smoking. However, possible risk factors include: genetics, cataracts, hypertension, sun exposure, farsightedness, light skin or eye colour, and a diet low in certain vitamins, minerals and antioxidants. These potential risk factors vary widely from one patient to the next. No two pairs of eyes are the same.
- Does sunlight affect macular degeneration?
Answer: Yes. It has been demonstrated that the blue rays of the spectrum seem to accelerate macular degeneration more than other rays of the spectrum. This means that very bright light, such as sunlight or it’s reflection in the ocean and desert, may worsen macular degeneration. Special sunglasses that block out the blue end of the spectrum may decrease the progress of the disease. Again, more research is needed in this area.
- Does hypertension (or medication for hypertension) affect macular degeneration?
Answer: Yes. Hypertension tends to make some forms of macular degeneration worse, especially in the “wet” form where the retinal tissues are invaded by new blood vessels. The medications used to treat hypertension have not been shown to have any direct effect on macular degeneration, but they may slow progression of the disease by reducing hypertension.
- Is ARMD hereditary – will my children be affected?
Answer: Several studies have found that family history of ARMD increases the risk of developing the disease. Therefore, if you have ARMD, it is even more crucial that your adult children over the age of 40 have regularly scheduled eye examinations. Early diagnosis through medical eye examinations at least every year offers eye care specialists the opportunity to provide counsel about appropriate options for possible treatment, rehabilitation and support services.
- Will both eyes be affected – what can I do to protect the vision I have?
Answer: It is very difficult to predict what will happen to the second eye if ARMD affects one eye. In some instances, vision is not affected. However, vision may change in the second eye over time. Approximately 42% of patients with wet ARMD in one eye will develop the same in the second eye over a period of five years. But again, it is difficult to predict the extent of the vision loss. IT IS THEREFORE IMPORTANT TO ROUTINELY VISIT YOUR EYE CARE PROFESSIONAL. It is important to consult your eye care provider to find out where you can find a low vision specialist who may be able to assist you with your specific needs.
- How fast will get ARMD progress – will I become totally blind?
Answer: While 85-90 percent ARMD patient have the less sight-threatening dry form of ARMD. Approximately 70% of those diagnosed with wet ARMD generally will maintain their peripheral, or side vision even in the later stages of the disease. You should not become completely blind.
- Is there anything I can do to enhance the vision I have left (e.g.technology, vision aids, rehabilitation, etc)?
Answer: Yes! There are number of things you can do to maintain and independent lifestyle. Your eye care provider can discuss with you available treatments, vision rehabilitation options such as low vision aids (e.g., strong reading or telescopic lenses, electronic devices etc.), support services, talking books (available at your local public library) and learn activities of daily living.
- How will my daily life change – can I drive a car, cook, read, sew write letters, live an active life, etc.?
Answer: Although peripheral vision usually remains normal, typical symptoms of both wet and dry ARMD may include difficulty seeing at a distance, difficulty doing detailed work like sewing or reading fine print, blurring of faces and difficulty distinguishing color, distortion causing edges or lines to appear wavy; and dark or empty spaces that block the center of vision.
However, through the proper use of low vision aids and rehabilitation to learn new skills to enhance daily living, an active lifestyle can be maintained.
Although you may not be able to drive a car, you can learn new ways to cook, read, sew, write letters, etc.
- What can I do to help prevent and cure macular degeneration?
Answer: Have annual routine eye examinations.See your ophthalmologist without delay if you notice any decline in your vision.