Tyler Wilfong was born with retinitis pigmentosa (RP), a rare collection of inherited eye diseases that slowly robbed his vision. Last year, he went to the Duke Eye Center, one of the few eye hospitals in the country performing gene therapy to halt the disease’s progression. Now Wilfong can work again and watch his baby boy grow. “It’s been life changing,” he said.
Retinitis Pigmentosa Causes Progressive Vision Loss
Wilfong of Lincolnton, NC, was 8 years old when his parents noticed he was having trouble finding a toy on the floor. He was diagnosed with retinitis pigmentosa, a condition that damages the retinal layers and causes vision loss over time. According to Lejla Vajzovic, MD, FASRS, a retina specialist at the Duke Eye Center, the first signs of RP are loss of night vision, then loss of peripheral vision, which narrows the field of vision. Eventually RP leads to tunnel vision and central vision loss.
Wilfong, now 36, described his world as darker as he grew up. “Everything was really blurry. In low light situations it was like blindness. I couldn’t play high school football because I couldn’t see under the lights. Everything in the gym is brown, dark brown hard wood, dark brown bleachers. It was hard to see.”
Afraid of Losing His Sight
While he had a driver’s license for about three years and never had an accident, Wilfong eventually had to stop driving. He was able to do some carpentry work but that had to stop too. “I felt like I was losing my independence. It had gotten to the point where I couldn’t walk around the grocery store. What’s bright to other people wasn’t bright to me.”
As the condition worsened, Wilfong said he was afraid “I was going to lose my sight.”
Because the disease is inherited, Wilfong underwent genetic testing in Winston-Salem to determine if his family members were affected. While none had RP, the testing uncovered that Wilfong’s mother and father carried a specific mutation in the gene referred to as RPE65. His local eye doctor knew that people with this gene mutation could qualify for gene therapy treatment.
The eye doctor referred Wilfong to Duke, one of the few eye centers in the country to offer the gene therapy known as Luxturna (voretigene neparvovec). Wilfong had the procedure on his left eye in 2023.
How Gene Therapy Halts Cell Degeneration
A healthy, artificially engineered RPE65 gene is packaged into a harmless virus that cannot cause disease and acts as a delivery vehicle. The virus is surgically injected precisely into the area of damaged cells responsible for vision loss. “The new healthy gene helps decrease the degeneration of those cells and helps stop the process that has been causing them to slowly die over time,” explained Dr. Vajzovic.
While every patient’s response is different, Dr. Vajzovic said clinical trials show the therapy can decrease the progression of disease and improve vision.
Gene Therapy for RP Has Been Life-Changing
The first thing Wilfong noticed in the days after the procedure was how many fingers he held up on his hands. Eventually the world became brighter, and he could see more details in low light situations. “Before, if there were no lights on, I couldn’t see inside the house.”
Now, he can find his new baby’s pacifier when it drops, see his baby’s mouth to feed him a bottle, and change his baby’s diaper without help. So far, his baby’s vision appears unaffected. “It’s been life changing,” Wilfong said. “Duke really came through. I’m looking forward to getting the other eye done.”
Duke Eye Center at the Forefront of Inherited Retinal Disease Research and Treatment
Gene therapy for RP is confined to a select few centers because of the complexities involved. The virus with RPE65 gene must be formulated in a specialty pharmacy. It must be thawed and mixed appropriately and used within hours by surgeons who are specially trained in the procedure.
Because inherited retinal diseases are so rare, it’s important to go to an eye center like Duke, where experts are specially trained to examine and diagnose people with RP and other rare inherited retinal diseases. The team includes genetic counselors who help diagnose the disorder and provide counseling on the implications of having certain genetic mutations. It also ensures access to advanced treatments and research.
As one of the leading eye centers in the country, Duke is involved in several clinical trials looking at other mutations to potentially be solved with gene therapy.