Types of Macular Degeneration
While age-related macular degeneration (AMD) is the primary cause of severe vision loss in individuals over 50 in the US, all macular degeneration is not the same.1
Types of macular degeneration
There are different types, with some being rarer than others. The features of each kind can vary, and treatment is different for each kind. Less common forms of macular degeneration include wet macular degeneration, Stargardt disease, and myopic macular degeneration.
Age-related macular degeneration (AMD)
Wet, exudative, or neovascular, AMD is one of the two kinds of age-related macular degeneration (AMD). It makes up only 10 percent of AMD diagnoses, but 90 percent of legal blindness.2 This kind of AMD occurs when blood vessels leak fluid or blood into the macula, affecting central vision. Wet macular degeneration is considered advanced disease; there is no early or mid-stage form of the disease.3
Treatment is focused on slowing down the progression of the disease, and if caught early, trying to recover some lost vision. Treatment can consist of injectable medications, laser treatment, and vision rehabilitation.
Dry macular degeneration, the other kind of age-related macular degeneration, is also called geographic atrophy. The macular tissue gradually thins out and breaks down, destroying the light-sensitive cells in the macula.1 This impairs central vision, and this vision lost cannot be restored or fixed.
Stargardt disease, also known as Stargardt macular dystrophy or juvenile macular degeneration, is an inherited disorder of the retina that causes progressive degeneration of the macula. Approximately 8,000 to 10,000 people in the US have the condition.4
Stargardt disease treatment
There is no treatment for Stargardt disease at this time, but people with the disease can take protective measures like avoiding smoking cigarettes or exposure to cigarette smoke, wearing dark glasses or hats when in the sun, and avoiding high doses of vitamin A from supplements. There are adaptive devices that can be used when vision becomes significantly impaired, usually when the person is in their 20s.
Myopic macular degeneration
Myopia is another term for nearsightedness and is often measured by the power of the lens needed to fix vision. Lenses are measured in units called diopters, and individuals wearing lenses of -6 diopters or more are considered very nearsighted, and have a higher risk of myopic macular degeneration (MMD).5 As the diopters get higher, the risk for MMD increases, especially over -10 diopters.
If an individual is very nearsighted, they may also be described as having “high myopia.”5 This is when there is increased distance between the cornea, which is in the front of the eye, and the retina, in the back. If there is even a little bit of abnormal distance, the retina can be stretched, causing cells in the macula to die.5 This is a slow, gradual process that causes a blind spot or loss of vision in the center of the visual field, a hallmark of macular degeneration.
Individuals can also develop wet MMD, where abnormal blood vessels grow into the retina and may cause fluid or blood to leak into the macula.5 While there is no treatment for the slow-progressing form of MMD, wet MMD is treated like wet AMD.6
Rare types of macular degeneration
Although some forms of macular degeneration are rare, they affect thousands and thousands of people, and the diseases may not get the attention or funding they deserve because of their rarity. Rare diseases often aren’t discussed with patients and there is often a lack of patient education because it’s rare – which means people aren’t knowledgeable about the symptoms or warning signs of the condition. It is exactly because of these reasons that it’s important to learn about rare forms of macular degeneration.
If you’ve been diagnosed with a rare form of macular degeneration, talk with your doctor about what this means for you, what treatment options are available, and whether perhaps a clinical trial or research study might be appropriate. With research constantly being done on rare diseases, this might be an option for you.