When I discuss Age-Related Macular Degeneration (AMD) with my patients, I always use the phrase, “it’s why seniors go blind.” While there are some exceptions, if you or a relative are an aged adult and have central vision loss, this is likely caused by AMD. According to the Centers for Disease Control and Prevention, an estimated 1.8 million people have AMD and another 7.3 million are at risk. Since we, and all eye care providers, want to prevent blindness it is important for all patients to know the facts about AMD.
What is it?
AMD, as the name implies is the degeneration of the macula. Your macula is an area of the retina, the tissue that lines the inside of the eye, which is responsible for fine detail and central vision. The macula is made up of millions of light-sensing cells. As damage to this area occurs, the center part of vision may become blurred or wavy, and a blind spot may develop.
Who is at risk?
When I discuss risk factors, I like to separate them into non-preventable (something you are born with) vs. preventable (something you can change.)
Non-preventable risk factors are age (more likely after 60 years old), family history of AMD, Caucasian race, female sex, and lighter colored eyes.
In the preventable risk factors category, I mainly discuss the major one which is smoking. Research has shown that smokers have four times the risk of developing AMD compared to past and non-smokers and that smokers may develop the disease earlier. In conclusion, it is SO important for your overall health and vision to quit smoking. Lower in the category of preventable risk factors is heart disease, high blood pressure, high cholesterol, obesity, increased sun exposure, and poor diet.
How is it detected?
While some patients may notice slightly blurred vision, most individuals will not notice early and intermediate stages of AMD. This is why a comprehensive dilated eye exam is so important. This exam will include testing visual acuity with the eye chart and checking for any distortions in your vision with an Amsler grid. Once your eyes are dilated, your eye doctor will look for any changes associated with AMD. If changes are noticed, your eye doctor may perform some ancillary testing including an optical coherence tomography (OCT) which shows a fine detail image of the macula, a photograph of the inside of the eye, and possibly a fluorescein angiogram. The fluorescein angiogram is when a dye is injected into your arm and quickly after the dye follows the bloodstream into the eye. If the dye leaks out of blood vessels then this can show a more severe form of AMD.
What happens if I have AMD?
If you have AMD, your eye doctor will determine if you have early, intermediate, or a severe/advanced form.
Unfortunately, there is no treatment for early AMD, but typically this is the form with the fewest or no symptoms at all. I recommend my patients with early AMD have a yearly dilated eye exam and discuss the preventable risk factors mentioned above. I also introduce an Amsler grid to these patients, to monitor changes at home.
Intermediate AMD is monitored more closely, typically with a dilated eye exam every 6 months, and Amsler grid at home. The National Eye Institute recommends nutritional supplements called the AREDS vitamins. It should be understood that these vitamins DO NOT cure AMD or restore already lost vision but it may delay the onset of advanced AMD, and it may slow vision loss in people who already have advanced AMD. These vitamins have been shown to only be effective in patients with intermediate or severe AMD.
Advanced AMD is the most visually devastating for patients, but it also comes in two forms. The treatable form of advanced AMD is called neovascular or wet AMD. This is when blood vessels grow underneath the retina. Your ophthalmologist will determine what treatment works best, but most of the time it is treated with injections in the eye and very close monitoring. Typically these patients are seen every 4-6 weeks. The untreatable form of advanced AMD is called geographic atrophy which is when large areas of the retina waste away. This is by far the most devastating form of AMD. The majority of these patients are legally blind and require visual aids. Fortunately, there is a whole area of eye care called Low Vision dedicated to providing care to individuals with low or no vision.
In summary, AMD is a serious eye disease and should be monitored closely. The best thing is to visit an eye care professional for a dilated eye exam every year.
Written by: Kirsti Roehm, O.D.