Inherited Retinal Disease

Knowledge is power: genetic testing for inherited retinal diseases

Posted on

A webinar hosted by the National Center for Children’s Vision and Eye Health and Prevent Blindness brought together several stakeholders—physicians, patients, and industry representatives—to discuss the importance of genetic testing for inherited retinal diseases (IRDs) and the current state of the field for patients living with these conditions.

The webinar, titled, “Pathway to Diagnosis: Genetic Testing for Inherited Retinal Diseases,” took place May 29, 2024. This article summarizes the key takeaways from the event.

Dawn DeCarlo, OD, PhD, CEO of Sight Savers America, moderated the event, noting, “It’s an exciting time in eye care in general.” Early in her career, she didn’t think much could be done to help these patients, but now, “We are looking at entirely different ways to care for people with IRDs,” she said.

Dr. DeCarlo indicated that knowledge is power: “If you have a condition and you know the gene mutation that is responsible for that condition, you then have the opportunity to follow the research in a more targeted way … and to discuss things at a higher level with your doctor … and to know if there is a clinical trial available to you. We want people to have the power to make good decisions about their health care.” Information gives patients the power to decide what is best for them.

Sheila Hickson-Curran, MCOptom, FAAO, Medical Affairs Leader at Johnson & Johnson Innovative Medicine Retina, discussed the genetic testing capabilities for IRDs, noting how the science has evolved tremendously over the last few years. “We can’t change what we inherit in our genes, but we can find answers, which can help inform your health and your family’s health and make life choices,” she said.

Natario Couser, MD, Associate Professor of Ophthalmology, Pediatrics, and Human & Molecular Genetics in Richmond, VA, then outlined 7 key signs of IRD:

  1. Vision problems that cannot be corrected
  2. Light sensitivity
  3. Trouble navigating in dim light conditions
  4. Challenges with peripheral vision
  5. Difficulty distinguishing colors
  6. Eye movement abnormalities
  7. Positive family history of IRDs

He also discussed the challenges associated with diagnosing IRD based on clinical suspicion alone without genetic testing:

  • Variable expressivity
  • Incomplete penetrance
  • Vision abnormalities not infrequently manifesting in the presence of a normal appearing fundus
  • Overlapping clinical features among different IRDs

On average, the journey to reach an IRD diagnosis in a child with a rare genetic disease is over a decade. In an experiment at his institution, Dr. Couser and colleagues found that the time from symptom onset to diagnosis was 15 years on average and involves multiple physician visits and increased costs.

The advantages of genetic testing include:

  • Help guide recurrence risk counseling
  • Give patients and families resources
  • Assist in developing a management strategy that includes appropriate referrals for syndromic cases for which other organ systems may be at risk
  • Clinical trials/treatments

Clinical trials in this space require a molecular diagnosis, not just clinical suspicion, so genetic testing is crucial to getting patients involved in clinical trials.

Rachelle Lin, OD, MS, FAAO, Associate Professor, Southern California College of Optometry at Marshall B. Ketchum University, talked about the importance of in-office provider-ordered genetic tests rather than direct-to-consumer versions that are not held to the same medical standard. She said it is important to help parents of children with medical conditions make informed decisions on genetic testing, including discussing the pros, cons, and limitations.

Pros of genetic testing include improving accuracy of diagnoses and prognoses, improving accuracy of genetic counseling, and developing mechanism-specific care.

Cons of genetic testing include the effects on family planning, patient emotions to information, and unwanted discoveries, as what people can learn from a genetic test “can’t be unlearned.”

She cautioned that even with current panels, results can be inconclusive or negative, and causative mutations can only be identified in up to 56% to 76% of patients with IRDs.

There are also barriers to genetic testing such as:

  • Costs
  • Access (transportation, distance, language barriers)
  • Mistrust or concerns with health system, genetic testing, research registries, etc.

Two patients living with IRDs spoke about their journeys.

Adriann Keve experienced vision problems that presented around age 8 years. On her journey to her Stargardt disease diagnosis, she was accused of making up the vision issues for attention and was recommended a psychiatrist. She said the journey took a toll on her self-esteem and mental health, and she now works to advocates for patients with vision issues, particularly young children.

Joy Thomas is another patient living with an IRD and is a Prevent Blindness ASPECT Patient Engagement Program graduate. Her journey started at age 5 years when she and her identical twin sister were diagnosed with early-onset blindness. Genetic testing revealed that her 2 younger siblings did not have the same mutation and thus did not suffer these eye issues.

To close out the webinar, Ben Shaberman, MS, MA, Vice President, Science Communications at the Foundation Fighting Blindness, discussed the positive research trends, including more than 50 clinical trials underway for IRDs, nearly 20 of which are human trials with meaningful efficacy observed, with vision being preserved or restored. This shows that the approaches being taken are working, he said.

He concluded by talking about the Foundation’s My Retina Tracker Registry®, which launched nearly 10 years ago to connect patients with researchers and companies recruiting for clinical trials. The registry is available globally to anyone with an IRD. To date, there are more than 30,000 registrants. Learn more about the registry.

The webinar was funded by Johnson & Johnson.