What is Age Related Macular Degeneration?
Age-related macular degeneration is a common cause of vision loss in people over
the age of sixty. You may already have it. Or you may be concerned because you are
at risk .
It progressively destroys your sharp central vision. This impairs your ability to
see objects clearly and makes it very difficult to undertake the normal tasks such
as reading and driving.
Age Related Macular Degeneration affects the macula, the part of the eye that allows
you to see things in fine detail. (The macula is located in the centre of the retina,
the light-sensitive tissue at the back of the eye.)
What you may see:
Age Related Macular Degeneration can cause loss of sharp central vision in one or
both eyes. With Age Related Macular Degeneration, you may have no obvious vision
loss. Or you may have one or more of the following vision problems:
- Fuzzy or blurry areas
- Distorted lines and wavy edges
- Faded color vision
- Dark spots in your central vision
- Vision that varies from day to day
How you may feel:
The thought of vision loss can be frightening. You may fear going blind. Or you
may worry about being unable to drive, read, or be independent. Although Age Related
Macular Degeneration can cause vision loss that ranges from mild to severe, it rarely
causes total blindness. Some aspects of your life may change, but Age Related Macular
Degeneration will not make your world go dark.
What you can do:
Whether you have Age Related Macular Degeneration or are at risk for it, there are
ways in which you can protect the vision that you have:
- Vision-monitoring and regular eye examinations can help you and your eye doctor (ophthalmologist) work together to preserve your vision.
- In some cases, laser treatment may keep Age Related Macular Degeneration from getting worse.
- Changes in your lifestyle can help protect your eye health.
There are many things you can do to adapt to vision changes if they occur.
Tips for families
When a loved one has Age Related Macular Degeneration, you can help. Encourage your loved one:
- To protect his or her vision.
- To have regular eye examinations.
- To use his or her remaining vision as much as possible.
- To stay active and involved.
The healthy eye:
The eye receives and processes light, allowing you to see. Central vision is the sharp detailed vision that you use when you look straight ahead. Peripheral vision is side-vision, the less acute vision that you may call 'seeing out of the corner of your eye'. Age Related Macular Degeneration affects central vision.
Mechanism of sight:- Light enters the eye through the pupil.
- The retina (inside lining of the eye) turns this light into signals.
- The brain turns these signals into visual images what you see.
The healthy macula:
The macula is the part of the retina where central vision takes place. The fovea
is the most sensitive part of the macula. The whole retina, including the macula
and the fovea, has several layers:
Types of macular degeneration:
There are two kinds of macular degeneration: dry and wet. Age Related Macular Degeneration
may be either kind. Dry macular degeneration is more common. It usually does not
cause severe vision loss. However wet macular degeneration is rarer, but it is more
likely to cause severe vision loss. Dry macular degeneration can sometimes develop
into wet macular degeneration.
Dry macular degeneration:
Dry macular degeneration may cause a slow and gradual decline in vision. The breakdown
of the RPE causes it. This breakdown damages the light-sensing cells. It may also
lead to the formation of drusen (yellow deposits) beneath the retina. These changes
may cause distorted or blurry vision. As the function of the macula is impaired
over time, the central vision is completely lost in the affected eye.
Amongst these two types of Age Related Macular Degeneration, the dry condition is
predominant. Over 85% of all the people who suffer from intermediate and advanced
Age Related Macular Degeneration have the dry-type condition.
Wet macular degeneration:
Wet macular degeneration may cause sudden loss of central vision. The growth of
new, weak blood vessels causes it. These blood vessels grow from the choroid below
or through the RPE. They may cause the macula to bulge, distorting vision. Fluid
leaking from these weak blood vessels, or scarring on the surface of the retina,
can cause dark or blurred spots in the field of vision.
Monitoring your vision:
- Have regular eye exams and check your vision at home as directed by your eye doctor.
- Doing this can help you catch eye problems early.
- This can help preserve the vision that you have.
Vision monitoring:
Check your vision often using the Amsler grid (at night). Note changes in your vision
and report them to your eye doctor. Keep in mind that you may have vision problems
that are not related to Age Related Macular Degeneration. Making sure that any problems
are treated helps you make the most of your remaining vision.
The amsler grid:
An Amsler grid is a chart that you can use at home to check your vision. Cut out
the grid below. Or your eye doctor may give you one. Use the grid regularly, as
directed by your eye doctor. If you notice vision changes, contact your ophthalmologist
as soon as possible.
- Use the grid in a well-lighted area.
- Wear glasses or contacts if you usually wear them.
- Hold the grid at your normal reading distance (about 16 inches).
- Cover your left eye.
- Look at the dot in the grid's centre with your right eye.
- While looking at the dot, notice if any of the lines appear wavy or disappear or if the boxes change shape.
- Jot down any changes from the last time you used the grid.
- Repeat with your other eye.
- If you have noticed any vision changes, call your eye doctor right away.
Vision and eye evaluation:
Your evaluation assesses two things: your vision and the health of your eyes. Vision tests help your doctor learn about how well you see. By examining your eyes your doctor can find out more about your eye health.
Your medical history:Your doctor will ask about your symptoms, age and health history. He or she may also ask about the medical history of your family and factors such as smoking, diet, and exercise. He will also undertake a routine eye examination.
Photographs of the retina:If your doctor thinks you may have wet Age Related Macular Degeneration, he or she may do an angiogram (a special photograph of the retina). For this procedure, dye is injected into a vein, usually in the arm or hand. It then travels to the eye. The dye highlights any abnormal blood vessels or leaking fluid. The doctor may do two angiograms using two different dyes. The whole procedure takes less than an hour.
Laser treatment:
In this procedure, a laser beam destroys the tiny leaky blood vessels. A high energy
beam of laser is directed at the blood vessels to destroy them and prevent further
blood and fluid leakage. This prevents further loss of vision. Only a small percentage
of people with wet Age Related Macular Degeneration can be successfully treated
with Laser.
Laser surgery is more effective when leaky blood vessels have developed away from
the fovea, the central part of the macula. The risk of new blood vessels forming
is not eliminated with Laser procedures, and further procedures may be necessary
in time to come.
Photo-Dynamic Therapy (PDT):
- In this type of therapy, the surgeon injects a drug called Verteporfin into the arm of the patient. This drug travels through the body and reaches the new blood vessels in the patient's eye. Verteporfin has a tendency to stick to the surface of the new blood vessels.
- In the next step of the procedure, the surgeon focuses light on the eye of the patient for around ninety seconds.
- The light activates the drug, which then destroys the new blood vessels. This retards the loss of vision. The benefit of Verteporfin is that it does not damage any other tissue except the new blood vessels.
- As light activates the drug, patients are advised to avoid exposure of their skin or eyes to bright light for five days after the procedure.
The therapy is painless and can be done within twenty minutes.
Keeping your eyes healthier:
Protecting your general health helps to preserve your eye health and your vision. These tips may help delay or prevent Age Related Macular Degeneration from progressing.
- Eat a healthy diet: You can help keep your eyes healthy by eating a balanced diet that includes plenty of fruits and vegetables.
- Leafy green vegetables such as spinach may be especially good for protection against Age Related Macular Degeneration.
- Ask your doctor about taking a daily multi-vitamin or other supplement.
- Use of Anti-oxidants & Multivitamins to delay the progress of Age Related Macular Degeneration
Control blood pressure:
High blood pressure can make eye problems worse. To help you control your blood pressure, your doctor may suggest :
- Regular blood pressure checks.
- Regular exercise.
- Cutting down on salt, fat alcohol, and caffeine.
- Weight loss.
- Stress reduction.
- Blood pressure medication.
Use sun protection:
Protect your eyes from damaging sunlight:
- Wear sunglasses. Look for ones that block UVA and UVB light.
- Sunglasses that block blue light may also help protect against Age Related Macular Degeneration.
- Wear a hat when outdoors. Choose a hat with a brim that shades your face.
If you smoke, quit:
Protect your eyes from damaging sunlight:
Smoking damages blood vessels throughout your body, including those in your eyes.
It can also worsen high blood pressure. If you smoke, ask your doctor about a programme
to help you quit.
Living with Age Related Macular Degeneration
Age Related Macular Degeneration may never cause you serious vision loss. But if
it does, certain changes in the way you do things can help you to stay active and
enjoy life.
Maximize benefits from what you have got:
There are many ways to make the most of the vision you have.
- Use your side vision. If you need to look at an object move it to one side and look at it out of the corner of your eye.
- Make sure that other vision problems are corrected.
- If a hobby or game requires close work, look for a similar one that doesn't depend on such detailed vision. For example, you may choose to switch from needlework to rug hooking.
Drive safely:
You may find that you're able to drive safely during the day, but not at night.
If glare is a problem when you drive, special tinted glasses may help. But be realistic.
If you can no longer drive safely, don't drive. Giving up driving can be hard, but
it may be the best way to keep yourself and others safe.
Your loved one may need more help from you if his or her vision worsens. Offer to help, but let your loved one tell you what kind of help is needed. Be ready to:
- Drive.
- Help with chores and errands.
- Help your loved one get out of the house and stay active.
- Help in social situations. For example, greet people by name so that your loved one knows who is nearby.
Making changes at home:
Certain changes at home can make life safer and easier. Friends or family can help.
A low-vision specialist or an occupational therapist can advise you.
Make your house safer:
Protect yourself from falls, burns, and other accidents:
- Improve lighting.
- Install automatic lighting indoors and out.
- Remove or secure rugs, cords, low tables, and other objects that might trip you.
- Install railings on stairs, patios, and decks.
- Mark the 'off' position on stove and oven controls with colours or raised markings.
Make daily tasks easier:
Arrange your house to make tasks easier. For example:
- Mark items such as spices or pill bottles with colours or textures.
- Mark the edges of kitchen counters with contrasting tape or paint.
- Arrange closets and drawers to make things easier to find by touch.
Low-vision aids :
Low-vision aids can help you with close work, such as reading and writing. They
can also help you to use appliances and tools.
Magnifiers and reading eye-wear :
These aids enlarge print, making it easier for you to read. Some have lights attached.
There are special magnifiers designed to help with certain tasks, such as sewing
or gardening.
Reading machines :
Reading machines display a page enlarged on a screen. These machines magnify print
many times.
Tips for families:
Low-vision aids can help your loved one function better and enjoy life more. To
help:
- Learn more about low-vision aids and where to find them.
- Find out about local community resources for people with low-vision.
Other low-vision aids:
These include:
- Large-button telephones.
- Large-print books and audio books, available at your local library or bookstore.
- Signature guides for writing-codes.
- Talking appliances, such as watches, alarm clocks, and calculators.
- High-contrast cutting-boards and other kitchen tools.
An active life with Age Related Macular Degeneration:
Living with Age Related Macular Degeneration can be a challenge. But making the
most of the vision you have can help you get more out of life. Support from friends,
family, a low-vision support group, or other community groups can also help.
VEGF Inhibitors
Neovascularisation or the development of new blood vessels is a potential sight
threatening complication seen in common retinal conditions like ARMD and diabetic
retinopathy.
Such diseases entail damage to the lining of the blood vessels in the retina that
causes the retina to produce chemicals called "Vascular Endothelial Growth Factors".
VEGF is known to cause the development of new blood vessels.
Recent advances in treating this condition involve the use of an intravitreal injection
of VEGF inhibitors that cause the regression of new blood vessel formation and reduces
the inflammatory edema associated with neovascularisation.
Three drugs are currently used to treat these conditions:
- Macugen
- Avastin
- Lucentis
Intra-vitreal Injections:
The presence of abnormally high levels of a specific growth factor in eyes causes
new blood vessels. Wet Age Related Macular Degeneration can now be treated with
anti-VEGF injections in the eye This drug treatment blocks the effects of the growth.
Patients will need multiple injections that may be given as often as once a month.
Such injections help retard the loss of vision and in some cases they have been
known to improve eyesight.
Macugen
Macugen was the earliest therapy approved by the FDA- for the treatment of all subtypes
of neovascular Age related macular disorders. Macugen addresses the abnormal blood
vessel growth and leakage that is considered the underlying cause of the disease.
Macugen may also provides considerable benefits over existing therapies for the
blood vessel leakage associated with DME.
Description
Macugen is an injection used to treat patients suffering from the wet form of age-related
macular degeneration (Age Related Macular Degeneration). This affects the central
part of the retina (called the macula), at the back of the eye and causes loss of
vision. The macula provides "central vision" that is needed for driving a car, reading
fine print, and other similar tasks. Wet Age Related Macular Degeneration is caused
by abnormal blood vessels bleeding and leaking fluid under the retina and the macula.
This causes the loss of vision.
Age Related Macular Degeneration is rare in people under 55 years of age. It is
more common in people 75 years of age - one in twenty of this age group is affected
by Age Related Macular Degeneration.
Suitability
Recommended for patients suffering from wet Age Related Macular Degeneration.
Benefits
- Macugen works by stopping the growth of new blood vessels that damage the macula.
- It slows down the loss of vision
Lucentis
Description
Lucentis (ranibizumab) is a humanized anti-VEGF antibody fragment that inhibits
VEGF activity by competitively binding with VEGF. Lucentis is injected inside the
eye (intravitreous injection) as an office procedure that is best performed by Ophthalmologists
with specialty training in Retina and Vitreous surgery.
Suitablity
Lucentis is an FDA approved treatment for wet macular degeneration. Wet Macular
Degeneration is a condition that is found in 10% of all the people with Age Related
Macular degeneration but it accounts for 90% of the cases of blindness caused due
to Age Related Macular Degeneration.
Benefits
- 1 : About 95% patients with wet macular degeneration maintain their baseline vision whilst on treatment with Lucentis.
- 2 : About one-third patients (34%-40%) GAIN vision and the effect is sustained over the course of Lucentis treatment (1 to 2 years).
Avastin
Description
Avastin is a recombinant humanized antibody to Vascular Endothelial Growth Factor
(VEGF). It binds and inhibits VEGF, a protein that plays a critical role in the
formation of new blood vessels to the tumor.
Suitability
Avastin is used to treat Age Related Macular Degeneration and similar conditions
since research indicates that VEGF is one of the causes for the growth of the abnormal
vessels that cause these conditions. Some patients treated with Avastin had less
fluid and more normal-appearing maculas, and their vision improved. Avastin is also
used, therefore, to treat macular edema, or swelling of the macula.
Benefits
Significant impact on limiting the growth of blood vessels.