Causes of Macular Degeneration in Young Adults and Children
Macular degeneration is most commonly associated with aging. But when symptoms start to show up in children or young adults, it can raise a lot of questions.
What are the causes of juvenile macular degeneration? Here’s what you need to know if your child starts to display symptoms of this particular form of vision loss.
What Is Macular Degeneration?
Macular degeneration is the leading cause of vision loss— more than cataracts and glaucoma combined—and it affects more than 10 million Americans. To understand what macular degeneration is, it’s important to know what the macula is and the role it plays in vision.
The macula is the very center portion of the retina. It’s a layer of light-sensitive cells that are responsible for focusing your central vision. The macula is what gives us the ability to do things like read, drive a car, recognize objects in front of us, and see colors, fine detail, and faces.
According to the American Macular Degeneration Foundation, the retina sends information based on the images we see via the optic nerve to the brain so the brain can process it. When it works, the macula at the center of the retina receives very detailed, specific information that it then sends along to the brain to create the images we see.
When the macula begins to degenerate as a result of disease or genetics, however, this information is not processed correctly. In the earliest stages of macular degeneration, the vision may not be affected, but as conditions worsen, those with macular degeneration may start to see wavy lines or experience blurred vision, and in the latest stages, central vision may be lost entirely.
Symptoms of macular degeneration include:
- The distortion of straight lines in one’s field of vision.
- Reduced central vision.
- A need for brighter lighting to see clearly.
- Difficulty adapting to low lighting.
- Trouble with facial recognition.
The Two Forms of Macular Degeneration
Macular degeneration comes in two forms: wet and dry. What are the differences between the two?
Dry Macular Degeneration
Dry macular degeneration isn’t about having dry eyes.
When people experience dry macular degeneration, they often have yellow deposits that have built up in their macula. These deposits, also called drusen, may not affect vision at first. However, as they grow in size and number, these drusen can cause vision to dim and distort. As the condition worsens, it causes the light-sensitive cells in the macula to thin and die, potentially leading to central vision loss.
Wet Macular Degeneration
Wet macular degeneration refers to the growth of blood vessels below the macula. These vessels can leak blood and fluid into the macula, causing straight lights to look wavy and then leading to blind spots and loss of central vision.
Eventually, these blood vessels try to heal themselves, forming a scar and resulting in the permanent loss of central vision.
In most cases, people with macular degeneration have the dry form of the condition, but it can evolve into wet macular degeneration. In total, about 10 percent of people get the wet form of macular degeneration.
What Leads Young Adults and Children to Develop Macular Degeneration?
In most cases, macular degeneration is a symptom of age. Ethnicity, family history, obesity (and corresponding high blood pressure and high cholesterol levels), and a history of smoking are common causes for age-related macular degeneration. There’s a 2.1 percent incident rate of macular degeneration among those over 40, which increases to 14 percent for those over the age of 80. But macular degeneration also occurs in younger people.
Early-onset macular degeneration, which affects children from birth to age 7, is an inherited genetic disease, as is middle-onset macular degeneration, which affects young people between the ages of 5 and 20. People in their 30s or 40s can also develop a form of the disease that is inherited.
So how does a young person develop macular degeneration? In children and young adults, juvenile macular degeneration is usually the result of one of two things: Stargardt disease or vitelliform macular dystrophy.
Macular degeneration affects around one in 20,000 children and teenagers, and about one in 10,000 have Stargardt disease. Stargardt disease is the result of a gene known as ABCA4, located on Chromosome 1, OMIM 601691. It is a recessive gene, which means that both parents have to be carriers, and then there’s a 25 percent chance that their children will have Stargardt disease.
ABCA4 is a critical gene that tells the body to produce a protein that blocks the normal circulation of energy and waste to the macula. Small particles of waste—called lipofuscin—build up, breaking down the rods and cones in the retina that are necessary to take in images.
There is currently no cure for Stargardt disease, although proper nutrition and eye protection like sunglasses that shield against UV-A and UV-B light and blue-light-blocking glasses can help slow the progression. Researchers are studying gene therapies, like the delivery of the healthy version of the ABCA4 gene to prevent the accumulation of lipofuscin, but these treatments are in the testing phases and are not available for wide-spread patient use yet.
Vitelliform Macular Dystrophy
Vitelliform macular dystrophy is another kind of juvenile macular degeneration. It is a genetic eye disorder that leads to progressive vision loss. It affects the retinal pigment epithelium layer underneath the light-sensitive cells at the back of the eye in the macula. Vitelliform macular dystrophy causes progressive vision loss and can affect central vision in one eye or both.
Vitelliform macular dystrophy, also called Best’s disease after Franz Best, who identified the disease in 1905, appears most often in children, and the severity of vision loss can vary greatly from person to person.
Best’s disease is also genetic, but is caused by a dominant gene, which means only one parent needs to be a carrier to pass on the disease, and children have a one in two chance of inheriting it. There is currently no treatment for Best’s disease, but traditional scientific and genetic research approaches may find useful treatments in the future.
If your child or young adult is experiencing signs of macular degeneration, it’s important to schedule an appointment with an eye doctor immediately. Regular eye care appointments can help identify problems early on and monitor any changes.
At Vision Source Plano, we’re committed to providing advanced vision care, including for patients who have eye diseases like Stargardt’s disease and vitelliform macular dystrophy. If you or your child is experiencing symptoms of macular degeneration, we’re here to answer your questions and provide ongoing care and careful monitoring.
We want to guide you through the health and care of your vision. Contact us today to learn more.
Disclaimer: The content on this blog is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of qualified health providers with questions you may have regarding medical conditions.