Genetic vision disorders are rare, but impactful. Learn what to expect.
Some health conditions are the result of external causes, like injury, lifestyle factors, germs, or aging. Others already exist at birth, as part of our genetics—either inherited from a parent, or as the result of a chance mutation in our genes. Inherited retinal diseases (IRD) are part of the second category. These diseases affect the retina, the membrane at the back of the eye which sends visual information to the brain.
Because IRDs are genetic, they’re not preventable, but they are rare. There are many different types of IRD, with many different symptoms and effects. Some IRDs stay constant throughout a person’s life, but they’re also often degenerative, meaning they worsen over time. They can appear at different points in a person’s life, and progress at different rates.
The unpredictable nature of IRDs means that childhood screenings, regular eye exams, and knowing your family medical history are all important tools for identifying them. IRDs can’t be cured, but treatments and strategies exist to manage them, and like with most medical conditions, they’re more effective the earlier they start. Here’s what you need to know.
IRDs come in many forms
“Inherited retinal diseases” is an umbrella term for a group of conditions that cause similar symptoms of vision loss or impairment. Although they may seem to have a lot in common, IRDs are the most genetically diverse group of disorders in humans. At least 280 genes have been identified as causes for IRDs.
That diversity means that each IRD is unique, with slightly different effects, progression, and treatments. And although IRDs are rare, some still crop up more often than others. These are a few of the most common disorders:
Leber Congenital Amaurosis
LCA appears earlier in life than most other IRDs, with vision symptoms starting in a baby’s first few months. It affects 2 or 3 of every 100,000 newborns, and causes significant vision problems that worsen over time. Other eye-related symptoms are common with LCA, including a thin or cone-shaped cornea (the clear covering at the front of the eye), crossed eyes, extreme farsightedness, or increased sensitivity to light.
Retinitis Pigmentosa
There are several types of RP, and they can first show up in childhood or at any time during adulthood. Light-sensitive cells in the retina slowly die off, causing a gradual loss of vision. Night blindness—trouble seeing in low light conditions—usually occurs first, followed by blind spots around the sides of your vision that eventually grow inward toward the center.
Achromatopsia
This condition affects the cells in your eye that see color, and is present from childhood. People with achromatopsia have little or no color vision, are extremely sensitive to light, and often have poor enough vision to qualify as legally blind. “Ordinary” colorblindness is different from achromatopsia, as it primarily affects the way a person perceives color, and doesn’t usually cause other significant issues.
Cone-Rod Dystrophy
Rods and cones are cells in the eye that detect light (rods) and color (cones). Cone-rod dystrophy involves these cells failing over time, usually starting in childhood with blurred vision and light sensitivity. Blind spots begin in the center of your vision and grow outward, eventually resulting in significant vision loss by middle age.
Stargardt Disease
Stargardt disease affects the macula, the small area in the center of the retina that’s also involved in age-related macular degeneration. The macula is responsible for sharp, straight-ahead vision, and when it is damaged, the center of your vision can become blurry and eventually go away. Stargardt disease may not be identified until adulthood, and doesn’t usually cause complete vision loss.
Choroideremia
The genes that cause choroideremia are on the X chromosome, meaning the disease appears far more commonly in men. Similar to retinitis pigmentosa, vision loss starts in childhood and progresses from the outer edge of vision inward, potentially leading to complete blindness in adulthood.
Your care provider can help you manage an IRD
As we’ve seen, the symptoms of an IRD can vary widely, and in many cases can mimic the symptoms of non-genetic eye conditions like glaucoma or diabetic retinopathy. This makes diagnosing IRDs a challenging and sometimes lengthy process, as your provider will want to rule out more common causes of vision loss before turning to IRD.
Beyond a comprehensive eye exam, testing for IRD might involve an electroretinogram, measuring the electrical response of the light-sensitive cells at the back of the eye. Your care provider will also take detailed images of your retina, and may test different aspects of your vision, like low-light or peripheral (edge) vision. Ultimately, you may be asked to provide blood or saliva for a genetic test, which can help confirm the exact IRD you have and guide your care provider to the right treatment strategies.
Those strategies might include:
- Tinted lenses to help with light sensitivity
- Glasses to help with near- or farsightedness
- Nutritional supplements
- Gene therapy
- Surgery to repair the retina or improve associated symptoms
- Artificial retinas
- Vision rehabilitation to help you navigate life with low vision
Regular checkups are essential
Vision changes are inevitable for most of us over the course of our lives, whether from IRDs or more common causes. Having a baseline understanding of your eye health and a trusted care provider in your corner will set you up for the best possible outcomes when changes start to happen.
Regular eye exams create a record of your vision as it is now, giving you something to compare against later. Your care provider can also help you build a medical history, both from your own records and from what you know about your family—which can reveal a lot about your risk for IRDs and other eye health conditions, and will help your provider pinpoint the best possible treatments.
Heritage vision plans connect you with dependable care.
Everyone will need vision care at some point in their lives—and over our decades in the industry, we’ve seen the difference that even an eye exam or a pair of glasses can make. That’s why Heritage’s mission is to make essential vision care as accessible as possible to everyone.
To get connected with our handpicked, nationwide provider network, use our Provider Search tool to find coverage in your area. Or, if you aren’t yet a part of the Heritage family, learn more about our individual plans and join today.