Macula

If you have dry macular degeneration changes you should have a comprehensive dilated eye exam at least once a year. If you have intermediate or advanced changes you may benefit from taking an AREDS formulation containing high levels of antioxidants and zinc. Because dry ARMD can turn into wet ARMD at any time, you should monitor your central vision with a test you can do at home known as the Amsler grid (provided here, can be printed out, or is available from FEC). Use the grid at least weekly to evaluate your vision for signs of wet ARMD. This quick test works best for people who still have good central vision. Check each eye separately. Cover one eye and look at the grid. Then cover your other eye and look at the grid. If you detect any changes in the appearance of this grid or in your everyday vision while reading the newspaper or watching television, arrange to be seen as soon as possible (image shows representation of what the grid may appear like if ‘wet’ macular degeneration begins to occur). If you have wet ARMD prompt treatment is important and you will need monthly examinations and often re-treatments to manage recurrence of leaking from the abnormal blood vessels. Studies show that people who smoke have a greater risk of recurrence than those who don't.

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Once dry ARMD reaches the advanced stage, no form of treatment can prevent vision loss. However, treatment can delay and possibly prevent intermediate ARMD from progressing to the advanced stage, in which vision loss occurs.

The National Eye Institute's Age-Related Eye Disease Study (AREDS) found that taking a specific high-dose formulation of antioxidants and zinc significantly reduces the risk of advanced AMD and its associated vision loss. Slowing ARMD's progression from the intermediate stage to the advanced stage will save the vision of many people.

Long-term tablets to protect you from vision loss (according to the AREDS study)

What is the dosage of the AREDS formulation?

The specific daily amounts of antioxidants and zinc used by the study researchers were 500 milligrams of vitamin C, 400 International Units of vitamin E, 15 milligrams of beta-carotene (often labeled as equivalent to 25,000 International Units of vitamin A), 80 milligrams of zinc as zinc oxide, and two milligrams of copper as cupric oxide. Copper was added to the AREDS formulation containing zinc to prevent copper deficiency anaemia, a condition associated with high levels of zinc intake.

Who should take the AREDS formulation?

People who are at high risk for developing advanced AMD should consider taking the formulation. You are at high risk for developing advanced AMD if you have either:

1. Significant (large, many) drusen in one or both eyes
   
   OR
   
   
2. Advanced AMD (dry or wet, with vision loss) in one eye.

Your optometrist may be able tell you if you have ARMD, and you may be referred to us to assess it’s stage, and your risk for developing the advanced form. We can then arrange preventative treatment with the AREDS formula when indicated.

This medication is not a cure for macular degeneration. It will not restore vision already lost from the disease. However, it may delay the onset of advanced changes. It has been proven to able to decrease the likelihood of vision loss in those at high risk by up to 37%, enabling them to maintain their vision.

Can people with early stage AMD take the AREDS formulation to help prevent the disease from progressing to the intermediate stage?

A large research study did not find any benefit of treating people with early changes of macular degeneration. If you have early changes then a comprehensive eye examination every year can help determine if the disease is progressing.

Can diet or daily multivitamin products provide the same high levels of antioxidants and zinc as the AREDS formulation?

No. The high levels of vitamins and minerals are difficult to achieve from diet or multivitamins alone. However, previous studies have suggested that people who have diets rich in green leafy vegetables have a lower risk of developing AMD.

Ninety percent of all people with macular degeneration have this type. One of the most common early signs of this disease are drusen.

More severe dry ARMD is represents the gradual loss of the function of the cells that ‘see’ light. The pigment cells that are involved in light detection become damaged, and the retinal tissue in the macula becomes thin (atrophic). As this occurs patients experience a progressive dimming of their central vision. With advanced changes there may be an area of missing vision (scotoma) when a person looks directly at things.

The most common symptom of dry ARMD is slightly blurred vision. You may have difficulty recognizing faces. You may need more light for reading and other tasks. Dry ARMD generally affects both eyes, but vision can be lost in one eye while the other eye seems unaffected.

What are drusen?

Drusen are yellow deposits under the retina. They often are found in people over age 60, and in themselves do not usually cause vision loss. They are easily seen and assessed with a comprehensive eye examination, and we may take photographs of the back of your eye to enable us to monitor changes over time.

Dry ARMD has three stages, all of which may occur in one or both eyes:

1. Early ARMD

Either several small drusen or a few medium-sized drusen. There are no symptoms, and very little chance of vision loss.

2. Intermediate ARMD

Either many medium-sized drusen or one or more large drusen. Some people see a blurred spot in the center of their vision. More light may be needed for reading and other tasks.

3. Advanced Dry ARMD

Loss of tissue (atrophy and pigment changes) causes changes in vision such as difficulty reading or recognizing faces until they are very close to you.

If you have vision loss from dry AMD in one eye only, you may not notice any changes in your overall vision. With the other eye seeing clearly, you still can drive, read, and see fine details. It is crucial that you are seen as soon as possible if there are any changes in your vision, and not to attribute these to your worse eye.

Macular degeneration is a common cause of vision loss. Also known as ‘Age related macular degeneration’ or “ARMD” for short, this does not mean that loss of vision is ever a normal part of getting older.

Instead, this is a disease which needs to be diagnosed and can be treated. At FEC we have the equipment and expertise to assess your eyes for this condition and to advise you about the best available treatment.

General information about macular degeneration

In many cases, macular degeneration advances so slowly that people notice only minor changes in their vision. However, in around 30% of people with this condition it can progress faster and may lead to a loss of vision in both eyes. ARMD is a leading cause of vision loss in New Zealanders 60 years of age and older.

People often refer to Macular Degeneration occurring in a “Wet” and “Dry” form. These terms are sometimes confusing because they have no relationship to whether your eye waters or how the eye feels. What they refer to are the changes present inside the eye – which are either of a slow loss of tissue (so could be imagined as things “drying” out), or of sudden worsening that involves swelling and hemorrhage in the retina, things that can be described as “wet”.

Where is the macula?

The macula is located in the centre of the retina, the light-sensitive tissue at the back of the eye. The retina instantly converts light, or an image, into electrical impulses. The retina then sends these impulses, or nerve signals, to the brain.

What are the symptoms

For dry ARMD: the most common early sign is blurred vision, such as difficulty reading. As fewer cells in the macula are able to function, people will see details less clearly in front of them, such as faces or words in a book.

For wet ARMD: the classic early symptom is that straight lines appear crooked, where previously they had been normal. This results when fluid from the leaking blood vessels gathers and lifts the macula, distorting vision. A small blind spot may also appear in wet AMD, resulting in loss of one's central vision.

How is macular degeneration diagnosed?

Examination of the retina is done by an eye surgeon, after enlarging (dilating) the pupil with drops. Usually an Ocular Coherent Tomography (OCT) scan is also performed, which is like a very fine detail picture taken through the retina. The picture (normal OCT.jpg above) on the right shows the usual structure of the retina, with the bright orange layer being the tissue on it’s outer surface. On the left is an OCT image showing the swelling (increased thickness) of a macula with ‘wet’ ARMD, the darker spaces among the green (nerve tissue) representing collections of fluid.

Some people also require a test known as a Fluorescein Angiogram, which is a series of special photos taken of the retina as a fluorescent dye is injected through a patient’s blood circulation. This shows area of abnormal blood vessels and leakage.

Treatment

When should I be seen?

Anyone over 50 years of age with a sudden change in their central vision should be seen promptly, especially if they have lost vision in their other eye from macular degeneration, or are known to be at risk. An initial visit for retinal photography by one of our technicians can be arranged at relatively short notice, and the pictures taken then will help Dr Bedggood determine when you should be seen and whether treatment is likely to be required.

Urgent treatment of macular degeneration is necessary for the ‘wet’ form, as without this it continues to worsen in the majority of cases until only limited central vision remains in the eye. New drugs, which need to be injected into the eye, are able prevent this severe loss of central vision, and in many cases to regain early losses as well.

Who is at risk for ARMD?

The greatest risk factor is age. People in middle-age have about a 2 percent risk of getting ARMD, but this risk increased to nearly 30 percent in those over age 75. Up to 1 in 4 of these people will suffer significant vision loss in one or both eyes (so around 8% of people over 75 will experience some loss of vision from this condition).

• Smoking. Smoking increases the risk of ARMD.
• Diet. A good diet, rich in green leafy vegetables, Omega-3 such as found in fish oils, and other anti-oxidants is probably protective against loss of vision.
• Obesity. Research studies suggest a link between obesity and the progression of early and intermediate stage ARMD to advanced ARMD.
• Race. People of European background are most likely to lose vision from ARMD.
• Family history. Those with immediate family members who have ARMD are at a higher risk of developing the disease.
• Gender. Women appear to be at greater risk than men.

Can my lifestyle make a difference?

Your lifestyle can play a role in reducing your risk of developing ARMD.

• Eat a healthy diet high in green leafy vegetables and fish.
• Don't smoke
• Maintain normal blood pressure.
• Watch your weight.
• Exercise

How is wet ARMD treated

It is only in he last few years that there has been an easily available, affordable, and very effective treatment for wet macular degeneration.

This treatment involves the injection of a specially designed antibody compound into the eye itself where it is able to directly get into the tissue affected by the abnormal blood vessels that cause wet ARMD. In New Zealand it is common to use a drug known as Avastin (Bevacusimab) in a very small dose to treat wet ARMD, with the other option being Lucentis, a similar drug licensed specifically for the treatment of ARMD. Both are likely to be as effective as each other and both need to be repeated at regular intervals in many patients to maintain good vision.

How is dry ARMD treated?

Once dry ARMD reaches the advanced stage, no form of treatment can prevent vision loss. However, a large scientific study carried out over 7 years showed that taking a specific, high dose, vitamin tablet can reduce the numbers of patients with macular degeneration suffering from severe visual loss in one or both eyes. Tablets are available on prescription for people who are at high risk for developing advanced macular degeneration.

You will need to have a retinal photograph or eye examination to determine if you have:

1. Significant (large, many) drusen in one or both eyes, or
2. Advanced ARMD (dry or wet, with vision loss) in one eye.

This medication is not a cure for macular degeneration. It will not restore vision already lost from the disease. However, it may delay the onset of advanced changes. It has been proven to able to decrease the likelihood of vision loss in those at high risk by up to 37%, enabling them to maintain their vision.

Can people with early stage AMD take the AREDS formulation to help prevent the disease from progressing to the intermediate stage?

A large research study did not find any benefit of treating people with early changes of macular degeneration. If you have early changes then a comprehensive eye examination every year can help determine if the disease is progressing.

Can diet or daily multivitamin products provide the same high levels of antioxidants and zinc as the AREDS formulation?

No. The high levels of vitamins and minerals are difficult to achieve from diet or multivitamins alone. However, previous studies have suggested that people who have diets rich in green leafy vegetables have a lower risk of developing AMD.