The most common cause of irreversible vision loss among the aged
What is Age Related Macular Degeneration?
Age-related macular degeneration
is a common cause of vision loss
in people over the age of sixty.
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:
How you may feel
- Fuzzy or blurry areas
- Distorted lines and wavy edges
- Faded color vision
- Dark spots in your central vision
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.
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.
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
The healthy macula
- 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 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. Wet macular degeneration is less common, but it is more likely to cause severe vision loss. Dry macular degeneration can sometimes progress to wet macular degeneration.
Dry macular degeneration
Dry macular degeneration may cause a slow and gradual decline in vision. In this condition, there is 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 Age Related Macular Degeneration have the dry-type condition.
Wet macular degenerationWet 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 through the breaks in 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.
Check your vision often using the Amsler grid. Note changes in your vision or any distortion in your visual field 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 all eye problems are treated adequately, 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.
How to use the amsler grid
- Use the grid in a well-lighted area.
- Wear glasses or contacts if you usually wear them,particularly for near vision.
- 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 assisted by fluorescein dye injection). 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.
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 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.
Control blood pressure
- 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
High blood pressure can make eye problems worse. To help you control your blood pressure, your doctor may suggest :
Use sun protection
- Regular blood pressure checks.
- Regular exercise.
- Cutting down on salt, fat alcohol, and caffeine.
- Weight loss.
- Stress reduction.
- Blood pressure medication.
Protect your eyes from damaging sunlight:
If you smoke, quit
- 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.
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. This can be achieved with the help of low vision aids.
- 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.
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.
Tips for families
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:
- 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:
Make daily tasks easier
- 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.
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 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 low vision aids helps to 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 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:
Other low-vision aids
- Learn more about low-vision aids and where to find them.
- Find out about local community resources for people with low-vision.
An active life with Age Related Macular Degeneration
- 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.
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.
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:
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. 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 (pegabtinib) 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™ works by stopping the growth of new blood vessels that damage the macula and therby slows vision loss.
Lucentis (ranibizumab) is a humanized anti-VEGF antibody fragment that inhibits VEGF activity by competitively binding with VEGF. Lucentis is injected inside the eye (intravitreal injection) as an office procedure that is best performed by Ophthalmologists with specialty training in Retina and Vitreous surgery.
Lucentis is an FDA approved treatment for wet macular degeneration.
- About 95% patients with wet macular degeneration maintain their baseline vision whilst on treatment with Lucentis.
- About one-third patients (34%-40%) GAIN vision and the effect is sustained over the course of Lucentis treatment (1 to 2 years).
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.
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.
It has a significant impact on limiting the growth of blood vessels.