When it comes to central or straight-ahead vision loss, people usually think of age-related macular degeneration that affects older adults. However, early-onset macular degeneration, also known as macular dystrophy and juvenile macular degeneration, is a vision problem that affects children, adolescents, and young adults.
Although there are different forms of juvenile macular degeneration, heredity is usually the cause. Since a mutated gene is responsible, your child may be at risk for one of the various types of the disease.
Stargardt Macular Dystrophy -- the most common type of juvenile macular degeneration -- occurs when a child inherits a recessive gene from each parent. Parents don't know they are carriers and don't have the disease themselves. While a child may complain of symptoms such as blurred vision, difficulty reading, small blind spots, and trouble seeing at night or in dim lighting, diagnosis often is delayed. That's because doctors can't always detect the disease during a routine eye exam.
Although vision problems may not become obvious until some point between the ages of 30 and 40, damage to the eyes can begin as early as age 6, according to the American Macular Degeneration Foundation. In most cases, damage starts to take place before age 20. The disease -- which affects both eyes -- occurs in about one in every 10,000 American children. Generally, symptoms come on gradually before they begin to progress more rapidly.
Vitelliform Macular Dystrophy
Vitelliform macular dystrophy, or Best disease, is a congenital disease that affects the retina of the eye. The disease is a dominant genetic disorder that runs in families. A child inherits the abnormal gene from one parent.
Vision may remain normal for years, although diagnosis usually is made during the childhood or teenage years. Sometimes the disease doesn't progress past the early stages, so some children never experience visual symptoms. Other individuals move through the various stages of the disease, although it may take years. When this happens, visual acuity deteriorates more at each stage. The disease's rate of progression varies from individual to individual and isn't something doctors can predict.
Symptoms include blurry vision, loss of central vision, and fatty deposits accumulating under the center of the retina (macula). Doctors are able to detect these fatty deposits during an eye exam. In the later stages, central vision loss can occur in one or both eyes.
Like Stargardt disease, there currently is no effective medical treatment to cure or slow the progression of Best disease. Visual aids such as electronic book readers, special eyeglasses, page magnifiers, and large print books are available to help a child compensate for central or forward-focusing vision loss.
Juvenile retinoschisis is another rare eye disease that occurs mostly in male children. The gene that causes the disease is found on the X chromosome, which comes from a child's mother. Women can pass the gene to their female children, who become carriers.Symptoms may include involuntary eye movements and strabismus (crossed eyes). Besides central vision loss, about half of individuals affected also lose side vision, reports the American Academy of Ophthalmology. In some cases, the retina becomes detached.
For more information, contact a specialist, such as Malkani Retina Center.