What Is Stargardt’s?
Stargardt Disease (Stargardt’s) is an inherited, juvenile form of macular degeneration. A genetic mutation causes protein to block the passing of nutrients and waste to and from the macula. The macula, or central portion of the retina, and its “cone” photoreceptor cells are adversely affected.
The retina is light-sensitive nerve tissue lining the back of the eye, containing photoreceptor cells that convert incoming light into electrical impulses which are carried to the brain and interpreted as visual images. There are two types of photoreceptor cells: the rods, which more densely cover the peripheral, or outlying, portion of the retina as well as the cones, which more densely cover the central portion of the retina (the macula) and are responsible for central vision, sharp visual acuity (detailed vision), and color perception.
When Stargardt’s is present, fat deposits accumulate abnormally underneath the macula and cones cease to function. As a result, central visual acuity gradually (and sometimes sporadically) declines beginning in childhood or adolescence and typically levels off between 20/200 and 20/400.
How Is Stargardt’s Diagnosed?
As central visual acuity declines, your child or teenager will have difficulty reading (or recognizing pictures, numbers, and letters if not yet reading), identifying faces and facial expressions, driving, and gathering all of the visual information on a television screen, computer screen, phone, or tablet. The child may notice blurriness or distorted vision and/or a blind spot in his or her vision.
Many children also notice difficulty visually adapting in dimly lit environments after coming indoors on a sunny day.
Due to the initial, slow progression of Stargardt’s, it is common for these symptoms to go unnoticed for the first few years or to receive a preliminary misdiagnosis. Central visual acuity (clarity) will continue to decline, and the child will be taken to an ophthalmologist for examination. The doctor will detect fatty buildup under the macula (yellow deposits) and ineffective cones; a diagnosis of Stargardt Disease will be given.
Alternatively, if a family member has a diagnosis of Stargardt’s, your child’s eyes should be examined by an ophthalmologist, and you may choose to undergo genetic testing to help determine an early diagnosis. An early diagnosis enables a person with the disease to prepare for its progression.
Are There Treatments for Stargardt’s?
There is currently no cure or standard, proven treatment for Stargardt’s; however, it is possible to slow the progression by protecting the eyes from sun damage with use of quality sunglasses and a brimmed hat while outdoors in the daytime.
To learn about current research advances for Stargardt’s treatment, including gene therapy, stem cell therapy, and drug clinical trials, read ARVO 2016: Emerging Drug Targets Toxic Build-Up in Stargardt Disease by Foundation Fighting Blindness.
How Would You Describe the Eyesight Stargardt’s and How Will My Child Function with It?
Before discussing the visual symptoms of Stargardt’s, it is important to understand the emotional impact of the diagnosis. Likely, your child is past early childhood and will fear upcoming changes when he or she hears, “You are losing your central vision.” Encourage your child to identify all feelings instead of suppressing them, connect with other children or teens with Stargardt’s, and utilize professional counseling. There is life beyond vision loss, though it may take much grieving (occurring all over again when vision noticeably deteriorates) and time before the entire family recognizes it.
Stargardt’s manifests with increasingly poor or absent central vision in both eyes (called central scotomas) and overall decreased “sharp” vision. As the disease progresses, color perception declines.
Stargardt’s makes it difficult, to the degree relative to the severity, to identify people and facial expressions when looking head-on; to access information or read from paper, a book, the wall, a classroom blackboard, or a digital screen (when in the child’s direct line of sight and when the object is small or has little visual contrast); to work with fine details such as needle threading; to participate in sports requiring the need to respond to oncoming objects or people; and to travel safely by walking, biking, or driving a car as straight-ahead dangers will be overlooked.
The following accommodations will help your child with the above-mentioned tasks.
- Learning to use peripheral vision for tasks, called “eccentric viewing.”
- Environmental adaptations such as high contrast environments, a well-lit room, high-intensity lamps, additional time to interpret what is seen, and allowing the child or teen to sit in a preferred seat, likely sitting toward the back of a room and off-center.
- Use of low vision devices such as a monocular (pocket telescope) for distance viewing.
- High-tech assistive technology such as screen-reading software or screen-magnification software for computer use.
- Near-vision optical devices such as a stand magnifier. The enlarged image of text will reduce the proportion of words in the central line of sight.
- Nonoptical devices such as outdoor use of sunglasses and a hat with a brim.
- Specialized glasses (prism-based or bioptic telescopic) may reduce blind spots, as explained in Glasses for Stargardt’s Disease by the International Academy of Low Vision Specialists.
- Alternative techniques for performing life skills and academic tasks from the teacher of students with visual impairments.
- Orientation and mobility (travel training) becomes necessary to navigate safely with the use of a cane and public transportation.
Your child’s teacher of students with visual impairments should perform a functional vision assessment to determine how your child uses his or her vision in everyday life and a learning media assessment to determine which senses your child primarily uses to get information from the environment. These assessments, along with an orientation and mobility assessment conducted by a mobility specialist, will give the team information needed to make specific recommendations for your child to best access learning material and his or her environment.
Resources for Families of Children with Stargardt’s