Granular corneal dystrophy is a rare condition in which tiny, opaque granules grow on the cornea and can cause severe pain, blurred vision, light sensitivity and watery eyes. Some patients have severe conditions and elect to have cornea transplants, notes Albert Jun, M.D., Ph.D., who is doing cutting-edge research on this rare but painful disease.
The protein deposits, Jun explains, are caused by genetic mutations in cells on the outer layer of the eye, at the precise point where the iris meets the white of the eye. Those cells produce too much protein, which migrates to the surface and collects on the cornea.
“Eventually, they can cover the cornea, clouding and compromising vision,” says Jun, Wilmer’s Walter J. Stark, M.D., Professor of Ophthalmology and chief of the Division of Cornea, Cataract and External Eye Disease.
In appearance, the granules, with their jagged edges, have been likened to breadcrumbs or to saltwater deposits on a car window. They can feel like little pebbles in the eye, Jun adds. For many with the condition, there is pain. The only treatments to date involve removing the deposits surgically or with a laser. But the deposits always return because the mutation remains. Jun hopes to put an end to that.
Among those supporting his work is Joanna Pedas. “Dr. Jun demonstrates the dedication, the passion and, honestly, the brilliance to make a difference,” she says.
Jun is attacking the problem using a gene editing technique known as CRISPR to understand and someday hopefully cure granular corneal dystrophy. “The only real cure is to replace those cells with healthy ones,” says Jun. “That’s where gene therapy comes into the picture.”
He believes the lessons he’s learning could be applicable to other types of corneal dystrophy and, quite possibly, to genetic conditions outside the eye.
He has collected cells from a patient and used CRISPR to “knock out” the DNA mutation in cells grown in a petri dish. The next step is testing the treatment in the lab using corneal tissue. The ultimate goal: to deliver the treatment directly to the patient’s eye. That day is still a long way off, but both Jun and Pedas are optimistic.
Along the way, Jun has to confirm that the gene editing is safe and that it works every time without fail. After that, tests in animals will follow. If all works, eventually there will be human trials.
All that hard work requires people and equipment, and that necessitates funding. Jun is fortunate to have a number of generous supporters, like Pedas, who are interested in his work on corneal dystrophies. She believes clear vision is a gift and that advanced research like Jun’s has a huge potential for cornea patients and beyond.
“We support him,” Pedas says, “because he’s not satisfied with the status quo. He truly is an inspiration.”