Age-related Macular Degeneration
(or AMD for short) is a condition that can effect your eyes as you get older, in the over 50’s, AMD is the leading cause of sight loss in Ireland, with 7,000 new cases in Ireland every year. If left untreated 17% of people will progress to advanced AMD within five years.
AMD is progressive and it is also painless. Armd often begins in just one eye and so early changes can go unnoticed. This is why regular eye tests are so important. While AMD may affect your detailed central vision, most people still retain useful peripheral vision.
Some of the important symptoms of AMD ( Age-related Macular Degeneration) include:
- Distortion, where straight lines may appear wavy or: bent. e.g. wall or floor tiles appear wavy
- Difficulty in reading or doing any other activity which requires fine vision
Difficulty in distinguishing faces. - Dark patches or empty spaces, which appear in the centre of your vision.
Age-related Macular Degeneration is detected during a rigorous eye examination that includes:
1. Visual Acuity Test – An eye chart that measures how well you see at various distances.
2. Dilated eye examination – Drops are places in the eyes to dilate the pupils. This allows the optometrist to perform a closer examination.
Factors that may increase your risk of macular degeneration include:
Age. Your risk of macular degeneration increases as you age, especially after age 50. Macular degeneration is most common in people older than 65.
Family history of macular degeneration. If someone in your family had macular degeneration, you’re more likely to develop macular degeneration.
Race. Macular degeneration is more common in whites (Caucasians) than it is in other races.
Smoking. Smoking cigarettes increases your risk of macular degeneration.
Obesity. Being severely overweight increases the chance that early or intermediate macular degeneration will progress to the more severe form of the disease.
Diet. A diet that includes few fruits and vegetables may increase the risk of macular degeneration.
High blood pressure. Diseases that affect the circulatory system, such as high blood pressure or high cholesterol, may increase the risk of macular degeneration.
Inflammation. Your immune system can cause swelling of your body tissues, which may increase the risk of macular degeneration.
Cardiovascular disease. If you have had diseases that affected your heart and blood vessels (cardiovascular disease), you may be at higher risk of macular degeneration.
Amsler Grid
The Amsler Grid is a quick and simple test which can help to determine whether you are experiencing the early symptoms of AMD.
Hold the grid around 12 inches (30cm) in front of your eyes (this is the average reading distance). If you wear reading glasses leave them on but do not wear distance glasses. Cover one eye with your hand and focus with your other eye on the centre dot. Check that you can see all four corners of the grid. If areas of the grid appear blurred, distorted, or in any way abnormal then you could be displaying the early signs of AMD.
If the Amsler Grid appears perfectly normal to you then you probably don’t have AMD. However, if you are over 50 and have not been to the optician in the last two years, you should seriously consider making an appointment now. It is also important to keep testing your eyes at home every two months using the Amsler Grid.
Treating AMD ( Age-related Macular Degeneration)
There are a number of proven treatments for people who have the most severe type of AMD (wet AMD).
Dry Armd: is the most common type affecting 90% of people who have the condition. Thankfully, it is less severe than wet Armd and usually vision loss is very gradual. At this time, there are no proven medical treatments for dry macular degeneration. Research has shown that vitamins can slow the progression of the disease. The Age-Related Eye Disease Study (AREDS) found that a combination of antioxidants and zinc can slow the progression of the disease by 25% and the vision loss by 19%. At any time, dry Armd can progress to wet macular degeneration which causes rapid vision loss.
Wet Macular degeneration cannot be cured. If diagnosed early, treatment may help slow progress of wet Armd and reduce the amount of vision lost.
Anti-VEGF Injections
Medications may help stop growth of new blood vessels by blocking the effects of growth signals the body sends to generate new blood vessels. These drugs including bevacizumab and ranibizumab are considered the first-line treatment for all stages of wet Armd. These drugs are injected directly into your eye. Generally these injections need to be repeated every 6 weeks approx to maintain the beneficial effect of the medication. In some instances vision may partially recover as the blood vessels shrink and the fluid under the retina absorbs, allowing retinal cells to regain some function.
Photodynamic Therapy and Photocoagulation can also be used to treat wet Armd in certain circumstances
Photodynamic Therapy (PDT)
This treatment does not produce a blind spot on the retina. The light is shone directly at the targeted tissue and the drug accumulates in these cells. It therefore reduces damage to normal surrounding tissue and allows the treatment to be given again as needed. It does not stop vision loss or improve vision in eyes already damaged by AMD
Laser Surgery
Only a small percentage of people with Wet AMD can be treated with laser surgery, as it depends on the location of the leaky blood vessels. The risk of new blood vessels is developing after laser treatment is high. Repeated treatments may be necessary.
For more information relating to AMD, visit the website www.amd.ie
