Age-Related Macular Degeneration (AMD)
One of the most common causes of vision loss in older adults in the US is a condition known as age-related macular degeneration (AMD). It’s estimated that one in five patients over the age of 60 have some form of AMD and it is one of the most common conditions that we treat at North Carolina Retina Associates.
The back of the eye is lined by a thin, photosensitive tissue known as the retina, which receives light signals coming through the eye and converts them into electrical signals that are sent to the brain via the optic nerve. The central portion of the retina is known as the macula. The macula has a high concentration of cones, which are the photoreceptor cells that enable our eye’s ability to perform a wide range of advanced central vision tasks, including seeing in fine detail, reading, recognizing faces, and more.
AMD occurs when the macular tissue weakens, atrophies, and deteriorates. Over time, this progressive condition can cause permanent vision loss.
Symptoms of Age-Related Macular Degeneration (AMD)
AMD affects central vision, which can cause a wide range of symptoms, including:
- Visual distortions, such as straight lines appearing wavy
- Darkened areas in your central field of vision
- Vision loss
Typically, AMD will not impact peripheral vision.
Types of Age-Related Macular Degeneration (AMD)
AMD is classified into two distinct types: dry and wet.
Dry, or Atrophic, Age-Related Macular Degeneration (AMD)
The vast majority of patients with AMD have the dry form of the condition, which is caused by the natural aging process. As we age, the macular tissue deteriorates and deposits of cellular debris known as drusen build up under the retina. When drusen deposits are small in quantity and size, they generally do not cause any noticeable symptoms. As they increase in number and size, however, they can start to cause visual distortions. Eventually, if more drusen accumulate and the macula becomes thinner, the macula may cease to function properly.
Dry AMD has a relatively slow progression, and vision loss is typically gradual. For many patients, the impact of dry AMD on your vision may be minimal; many patients with dry AMD aren’t even aware that they have the condition until they start to experience noticeable symptoms or it's detected during a routine eye exam. Once diagnosed with dry AMD, patients must monitor their vision regularly and talk to their ophthalmologist right away if they notice any changes to their vision. This is because dry AMD can eventually transition into wet AMD, which is far more damaging.
Wet, or Exudative, Age-Related Macular Degeneration (AMD)
Wet AMD only accounts for about 10% of AMD cases. The main characteristic of wet AMD is the growth of abnormal blood vessels under the retina, also known as choroidal neovascularization (CNV). Unlike regular blood vessels, these new blood vessels are prone to breaking and can leak blood and fluid into the macular area, ultimately causing blurriness and distortions of central vision. Vision loss from wet AMD is generally much quicker and more noticeable than from dry AMD.
The risk of vision loss increases as the abnormal blood vessels continue to grow and leak. If the abnormal blood vessels continue to grow and leak. When it comes to preserving your central vision with wet AMD, time is of the essence. Early detection and diagnosis of wet AMD are critical so that you can receive vision-saving treatment as soon as possible.
Risk Factors for Age-Related Macular Degeneration (AMD)
The primary risk factor for developing AMD is being over the age of 50. Additionally, several other risk factors can increase your chances of developing AMD, including:
- Having a family history of AMD
- Having light-colored irises
- Unmanaged underlying conditions, such as high blood pressure, diabetes, or heart disease
- Consuming high quantities of saturated fats
- Long-term exposure to sunlight without protection
How Age-Related Macular Degeneration (AMD) Is Treated
Preventive Care for Dry Age-Related Macular Degeneration (AMD)
At this time, there is no cure or specific treatment for dry AMD; however, preventive measures can be taken to stave off the development of wet AMD. This includes:
- Getting any underlying conditions that exacerbate AMD under control
- Eating a diet consisting of foods that are good for eye health (e.g. dark leafy greens, oily fish, citrus fruits, nuts, etc.)
- Engaging in physical activity on a daily basis
- Not smoking
- Protecting your eyes from exposure to UV rays
- Starting a vitamin therapy regimen as directed by a doctor
Patients with dry AMD should also monitor their vision daily so that they can detect any changes quickly. This can be done using an Amsler grid, which is a simple chart consisting of horizontal and vertical lines that form a grid pattern and a dot in the center. When used correctly on a regular basis, the Amsler Grid can help you detect whether or not you’re experiencing any visual distortions, such as wavy lines.
How to Use an Amsler Grid: Step by Step
- Wear whatever glasses you normally wear for reading.
- Use the grid in an area that has good lighting.
- Hold the grid approximately 12 to 15 inches away from your face.
- Cover one eye and focus your uncovered eye on the dot in the center.
- As you focus on the center dot, take note of whether the lines of the grid look straight or appear distorted. Distortions can appear as wavy lines, blurred areas, darkened areas, or blank.
- Repeat these steps with the other eye.
If you detect any changes or notice unusual visual distortions, contact your ophthalmologist immediately.
Treatment for Wet Age-Related Macular Degeneration (AMD)
Wet AMD is commonly treated with a class of medications known as anti-vascular endothelial growth factors (anti-VEGF). These drugs include Avastin (bevacizumab), Lucentis (ranibizumab), and Eylea (aflibercept). They help to curtail neovascularization by inhibiting the growth of abnormal blood vessels. Anti-VEGF drugs are administered via intraocular injection, meaning they are injected directly into the eye. The eye is numbed before injection, making it a relatively painless procedure. Anti-VEGF medications often have great success in stabilizing and improving vision. All of our doctors have significant experience performing these painless injections.
Schedule a Consultation
All of the physicians at North Carolina Retina Associates have extensive experience in the diagnostic, medical, and surgical care of age-related macular degeneration. Visit us today for comprehensive care for dry and wet AMD.