Age- related macular Degeneration
Introduction to AMD
What is Dry AMD
Diagnosis of Dry AMD
Treatment of Dry AMD
The Amsler grid
What is Wet Age-related Macular Degeneration?
Types of Wet AMD
What are the symptoms of Wet AMD?
Will I lose my vision completely?
How fast does it progress?
How is it diagnosed?
How is Wet AMD Treated?
Its your vision - Hold on to it
Living with AMD
Glossary of terms
If you are like many people, you probably don't know a lot about Age-related Macular Degeneration (AMD). Even if you already have it, you may not fully understand what's going on inside of your eyes. This report has been structured to meet the needs of people who may be at risk of developing AMD and for those who have recently been diagnosed with it. There are five sections to this report:
Introduction to AMD - general information about Age-related Macular degeneration that everyone should be aware of.
Risk factors - for everyone but especially if you are over 45 years of age, because you will soon be in the age group that is susceptible to developing AMD.
What is Dry AMD? - A short summary of the most common form of AMD.
What is Wet AMD? - A simplified explanation of a very complex disease
Living with AMD - Practical information and tips for anyone living with AMD.
As its name suggests, Age-related Macular Degeneration is a disease linked to age. Specifically, people over age fifty. in spite of the fact that AMD is the leading cause of severe vision loss and legal blindness in people over 50 in the western world, it is relatively unknown. We say knowledge is power so why don't we take a few minutes to learn about AMD you never know it may help you - Read on!
AMD is a chronic, age related, degenerative disease of the macula. the macula is a very small and specialized area in the center of the retina. The macula allows you to see fine details directly in front of you such as words in a book, the words on this webpage or images on television. So while the entire retina lets you see that there is a book in front of you, the macula lets you see what is written in the book.
There are two types of AMD, Dry AMD and Wet AMD. Generally speaking, Dry AMD progresses quite slowly and is usually less severe than the wet type. But both types damage the macula and both can take away your central vision, which means the images you see directly in front of you.
With impaired central vision you may not be able to some of the things that you normally take for granted, like reading, driving, a favorite hobby, or surfing the internet.
Because AMD affects only your central vision, you wont ever be totally blind. You will still have your peripheral vision or side vision, and with the help of vision rehabilitation and vision aids you should be able to maintain your independence.
Early detection and intervention is key to preventing or delaying vision loss. In the case of Dry AMD, unless its detected in a routine eye exam, you may not even realize that you have the disease until it reaches an advanced state. this is due to its usually slow and painless progression over a period of years and the ability of one eye to compensate for any weakness in the other.
On the other hand Wet AMD can strike with alarming speed, causing severe and irreversible central blindness, often within months, sometimes even weeks. All of this makes a strong case for visiting your eye doctor regularly, especially if you determine that you are at risk.
There are a number of factors both in and out of your control that can put you at increasing risk for developing AMD. Knowing what they are might aspire you to make certain lifestyle changes or modifications that can help you reduce the risk. Some of the known and suspected risk factors that you can't do anything about are:
Age: Risk increases with an advancing age; from 8.5% for people 43 to 54 years of age to a high 36.8% for people over 75
Family history of AMD
Gender: females are more susceptible
Race: Light skinned people are more likely to develop AMD than dark skinned people
Blue or light colored irises: Light-colored eyes allow up to 100 times more light to reach the retina than dark colored eyes and there is less melanin (pigment) to absorb it
The following are risk factors that you CAN do something about:
Diet: A diet in low antioxidant vitamins and minerals is a significant risk factor.
Excessive sunlight exposure
High blood pressure
Obviously you cant change everything that puts you at risk but wherever you can consider making any lifestyle changes that will reduce your risk.
Most of the time, AMD will begin as the less severe dry type and for 85-90% of people, it will remain that way. Dry AMD can develop in one eye or in both eyes.
The early stage of Dry AMD usually begins with the appearance of drusen. Drusen are small white or yellowish deposits that begin to accumulate in one of the deepest layers of the retina due to a breakdown in its normal function. You will not be aware that these deposits are forming.
As the retinal layer continues to break down, an abnormal amount of drusen begins to build up. This build-up begins to disrupt the layers above it, eventually damaging the layer of photoreceptor cells (the cells that receive visual images from the lens), resulting in "blank" or blind spots in your central vision field.
As Dry AMD progresses from early to later stages, more cells break down and begin to waste away. At the same time, drusen continues to build up and eventually, additional, larger blind spots are formed.
As the disease continues to progress, the likelihood of it turning into the more severe Wet AMD significantly increases as well. According to the Age-related Eye Disease Study (AREDS), a large North American study of the effects of vitamins on Dry AMD, up to 43% of people with late stage Dry AMD can progress to the even more aggressive form of AMD within five years. (reference: a randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E, Beta Carotene, and Zinc for Age-Related Macular Degeneration, and vision loss. AREDS report 8. Archive of ophthalmology, October 2001)
With this type of prognosis. it's important to be proactive and do everything possible slow the progression of the disease. Your eye doctor should work with you to develop a plan to do that. What is most important is keeping all your schedules check-ups because monitoring the progress of AMD can be one of the best defenses against severe vision loss.
Dry AMD might first be noticed during a routine eye examination by your eye doctor, or you might have made a special appointment because you noticed something odd was happening to your vision. Ether way, a proper diagnosis of AMD should be left to an optometrist or ophthalmologist.
Since Dry AMD develops quite slowly, it can affect the vision in your eye without you being aware of it. That's because your eyes and brain are good at compensating for weakness. So if AMD is compromising vision in one eye, the god eye will adjust, making up for the other's deficiency. Regular visits to your eye doctor are critical for early detection and the preservation of your vision.
Treatment of Dry AMD is focused on monitoring and slowing the progression of the disease. Your eye doctor will want to monitor your progress at specific intervals in his office, and you will also be told to monitor your vision at home with the Amsler Grid. You should also consider making any modifications to your lifestyle that will help to slow the progression of the disease. your eye doctor will discuss all of these options with you.
Perhaps the most important thing you can do is heed your doctors advice about vitamin supplements. Specific high-dose ocular vitamin therapy as outlined in the ARED Study has been shown to delay the progression of Dry AMD and preserve vision. by doing so, the chances of progression to Wet AMD may also be reduced. One such vitamin, available at most pharmacies without a prescription is Vitalux. It contains the exact formula proven to delay the progression of AMD and preserve vision. Additionally, Vitalux contains the two carotenoid antioxidants lutein and zeaxanthin, which have been found to be beneficial in protecting against AMD.
The Amsler Grid is a useful and simple and efficient tool for monitoring your central vision. It's a test that works well and you can even do at home. Its regular and proper use will alert you to any changes in your vision.
Instructions for testing your sight/vision using the Amsler grid:
Test your vision with proper and adequate lighting.
Wear your reading glasses (if you use reading glasses) or look through the reading portion of your bifocals (if you normally read with spectacles).
Hold the Amsler grid (graph paper) at normal reading distance (about 14 inches).
Cover one eye at a time with the palm of your hand or an eye patch.
Stare at the center dot of the chart at all times.
It is important to not let your eye drift from the center dot!
Ask yourself the following questions as you check each eye separately:
Are any of the lines crooked or bent?
Are any of the boxes different in size or shape from the others? As you continue to look at the center dot, check to see that all the surrounding lines are straight and all the squares are the same size.
Are any of the lines wavy, missing, blurry, or discolored?
If you have answered 'yes' to any of the above - contact your doctor immediately!
Wet AMD is so named because of the involvement of blood in the deepest layers of the retina. In a process called choroidal neovascularzation (CNV), new and abnormal blood vessels spontaneously begin to grow beneath the retina and push their way up through it. Imagine they're like tree roots or weeds growing up through the cracks in the pavement. Being week and abnormal, these new vessels leak their contents of blood and fluid into the retina which separates and lifts up the other layers like a blister. This process finally disrupts the photorecepters ( the cells that receive the visual images from the lens), leaving them unable to transmit visual signals to the brain. This results in "blank" or blind spots in the visual field.
Left alone, this process eventually results in the growth of scar tissue which in turn, causes severe and permanent central vision loss. Perhaps surprisingly, there is no pain associated with the entire process.
Although Wet AMD can occur spontaneously, it's usually preceded by Dry AMD, which makes regular check-ups especially important. Wet AMD is more aggressive than Dry AMD and does not occur as frequently accounting for ten to fifteen percent of all AMD cases. It can cause rapid, sever and permanent central vision loss in a matter of weeks. Early detection is critical in order to start any treatments that might help preserve your vision.
There are various types of Wet AMD that have been named after the type or pattern of leakage that is present in the retina. Some of these types respond to treatment better than others. Only an eye doctor who specializes in AMD can determine which type you have and the method by which it should be treated.
Straight lines appear wavy or distorted (metamorphopsia)
Blank spots in the central vision (stotoma)
Any combination of the above
You will probably be the first person to detect the onset of Wet AMD when you notice that your vision has suddenly changed. If you already have Dry AMD, you might first notice a change on your Amsler Grid test. If you're not aware that you have any kind of AMD, your vision might suddenly blur, you may see a blank spot in your visual field, or things that should be straight appear bent or wavy.
Often accompanying the distortion and vision loss is a decrease in contrast sensitivity, which is the inability to distinguish dark from light. A loss of color perception is also part of AMD.
No. However the eventual outcome of untreated Wet AMD can be severe and permanent central vision loss, with vision dropping to legal blindness or lower. In AMD, total blindness or darkness almost never occurs because the disease does not affect the entire retina, just the central macula. So while someone with AMD may experience extremely poor vision in their central visual field, their peripheral vision is not impaired.
Unlike Dry AMD which progresses relatively slowly and may go unnoticed for years, Wet AMD is more aggressive and can cause severe vision loss in a matter of weeks or months. The speed at which Wet AMD progresses is dependent on a variety of factors. And once you have wet AMD in one eye, the chances of it developing in your other eye are significantly increased.
Only an AMD specialist, such as a retinal specialist, can make a definitive diagnosis; however your regular eye doctor can usually detect the presence of Wet AMD based on your symptoms, medical history and a basic eye exam including a dilated retinal exam. That's why regular eye exams are important because early diagnosis gives you a better chance at preserving more of your vision.
If your regular eye doctor suspects Wet AMD, you will be referred to a specialist. There, you will most likely undergo a dilated retinal exam followed by Intravenous Fluorescein Angiography (IVFA), a series of specialized photographs of your macula. These photographs will show what types of changes have occurred at the back of your eye. Based on these pictures, your specialist will recommend a specific course of action.
Current treatments for Wet AMD include laser photocoagulation and Photodynamic Therapy (PDT). Your specialist will recommend the best treatment for the type of wet AMD that you have. You should be aware however, that the goal of treatment is to delay or halt disease progression, they do not always restore vision already lost to the disease.
You need to be aware that the treatment of Wet AMD is a process that involves you, your eye doctor and your AMD specialist working together to slow down and limit the amount of vision loss. Because wet AMD is a chronic disease, constant monitoring of your progress is essential. That means doing your Amsler Grid tests as directed and keeping all scheduled appointments, whether for a check-up or additional treatments.
Your vision is very very precious - do whatever is in your control to hold onto it and keep seeing. While some degree of vision loss is inevitable with AMD, there are specific things you can do that may help delay it:
Visit your eye doctor or AMD specialist regularly - do not miss any scheduled appointments
Take the specific Ocular Vitamin supplements recommended by your eye doctor immediately
If you notice a change in your vision or your Amsler Grid test, contact your eye doctor immediately
Stop smoking - Get help if needed but stop smoking
Improve your diet - include more fresh fruits and vegetables, especially dark green leafy vegetables like spinach
Maintain a healthy body weight
Avoid excessive exposure to direct sunlight - wear sunglasses and a wide brimmed hat to protect your eyes from UV light
Keep high blood pressure under control
Be proactive about vision rehabilitation and the use of visual aids
A diagnosis of AMD does not mean an automatic sentence to a life of blindness, however the disease can have a profound effect on your quality of life. A significant loss of central vision can severely impact your ability to function as before, making things you have always ten for granted such as reading, viewing the internet, driving and watching television extremely difficult. But since your peripheral vision is not directly affected by AMD, you should still be able to function independently with the help of visual aids and rehab.
One of the most difficult things to overcome however is the emotional toll that vision loss takes. On the first diagnosis people can experience a range of emotions including shock, disbelief, denial, resentment, anger, rage, sadness, and loss. Most people also go through a period of depression, which, unchecked, can lead to even more problems than just coping with vision loss. Ask for help if you need it. Your loved ones, family, friends and even others are there to help you.
Learning to carry on in new ways is the key. people who learn to adapt so that they may continue to do the things they love fare much better. For example, if reading is your passion, you can adapt by using a magnifier or listening to audio books which allow a continued independence and confidence.
Low vision rehabilitation and a solid support network of family, friends, AMD support groups can all help you cope with vision loss.