From the minute we wake up until we go to sleep, our eyes help us navigate the world. Like a finely tuned camera, each part of our eyes has a specific job to do.
Our dome-shaped cornea, the front layer of the eye, lets light through and bends it to help us focus. Some light enters through the small opening of the pupil. The iris, the colored part of the eye, controls how much light the pupil can let in. This light then travels through the lens of the eye, which works with the cornea to focus the light on the retina. The retina, located at the back of our eye, is sensitive to light. It contains special cells called photoreceptors that convert light into electrical signals that go to your brain and convert those signals into the images you see.
Sometimes something can go wrong with one of the parts of our eyes. A rare group of disorders affecting the retina are called hereditary retinal dystrophies (IRDs). These groups of diseases are hereditary, meaning they run in families. It is caused by mutations or malfunctions in at least one gene that is not working properly. About 300 are known to play a role in these diseases.
Some IRDs can progress slowly, while others can change vision much faster. Some can cause vision loss.
“It is important to understand that these diseases are relatively rare. But for people who have an IRD, it can be life-changing,” says Shree Kurup, MD, FACP, a retinal specialist at University Hospitals Cleveland Medical Center. “But what is important to know is that early diagnosis of any of these diseases can absolutely improve life. We may not be able to cure every IRD, but we are making significant strides in learning more about the hundreds of genes that can cause it.”
There are more than 260 genes that can cause IRDs. But getting a diagnosis is more complicated than a routine eye exam. “There can be many reasons for blurred vision, and an IRD will not be an eye doctor’s first thought,” says Matthew MacCumber, MD, PhD, a retinal specialist at Rush University Medical Center. There is a great deal of variety among all IRDs, so making an accurate diagnosis can be difficult. “Sometimes patients have been misdiagnosed for years, and when they finally get a clear, accurate diagnosis, it’s almost a relief because they can finally put a name to their problem,” says MacCumber.
To make a diagnosis, doctors rely on a series of specialized tests that give them information about many aspects of your vision. A genetic test will tell you exactly what genetic mutation you have and can help your doctor confirm your diagnosis. It will also give you and your family important information about your illness, how you may need to plan for your own future and how it may affect other family members and future generations.
“It’s important to spend a lot of time with people, to explain to them how an IRD can change their lives,” says MacCumber. “Early diagnosis also gives patients early access to a team of experts who can help them.”
An early and accurate diagnosis can also help you enroll in a clinical trial. This gives you the opportunity to try new therapies before they are available to the general public. Although almost no IRDs currently have treatments, doctors are hopeful about the future of gene therapies. In clinical trials of such therapy, patients reported being able to get rid of some devices designed to help people with vision loss see and read faces.
“Gene therapy is the future of IRDs and we’ve come a long way in genetic testing. We are learning more and more about these diseases. I absolutely 100% recommend that patients participate in a clinical trial if they are eligible. This is how we’re going to find cures,” MacCumber says.
The most important thing for the majority of people with IRDs right now is not to give up hope. “Imagine how hard it can be for a parent to hear that their child is losing their sight, or how hard it is for an active adult to hear that they may need to change things in their life,” says Kurup. “IRDs are very complex, but every patient is an individual. For these people, knowledge really is power, and the sooner they gain that power the better.”