Stem cells from one eye show promise in healing injuries in the other

Team Udayavani, Aug 19, 2023, 9:35 AM IST

Phil Durst recalled clawing at his face after a chemical from a commercial dishwashing machine squirted into his eyes, causing “the most indescribable pain I’ve ever felt – ever, ever, ever.” His left eye bore the brunt of the 2017 work accident, which stole his vision, left him unable to tolerate light and triggered four to five cluster headaches a day.

Then he underwent an experimental procedure that aims to treat severe injuries in one eye with stem cells from the other. “I went from completely blind with debilitating headaches and pondering if I could go another day – like really thinking I can’t do this anymore” to seeing well enough to drive and emerging from dark places literally and figuratively, he said, choking up.

The 51-year-old from Homewood, Alabama, was one of four patients to get stem cell transplants as part of the first U.S. study to test the technique, which could someday help thousands. Though additional treatment is sometimes needed, experts say the stem cell transplant offers hope to people with few if any other options.

Results of the early-stage research were published Friday in the journal Science Advances, and a larger study is now underway.

The procedure is designed to treat “limbal stem cell deficiency,” a corneal disorder that can occur after chemical burns and other eye injuries. Patients without limbal cells, which are essential for replenishing and maintaining the cornea’s outermost layer, can’t undergo corneal transplants that are commonly used to improve vision.

Dr. Ula Jurkunas, an ophthalmologist at Mass Eye and Ear in Boston who was the principal investigator for the study, said the experimental technique involves taking a small biopsy of stem cells from the healthy eye, then expanding and growing them on a graft in a lab at Dana-Farber Cancer Institute in Boston. A couple of weeks later, they’re sent back to be transplanted into the injured eye. Durst was the first patient to undergo the procedure.

“The great part of it is that we’re using a patient’s own tissue,” not donor tissue the body might reject, Jurkunas said.

She said this method is better than a different procedure that takes a very large piece of stem cells from a healthy eye for use on an injured eye – but risks damaging the good eye.

Both of Durst’s eyes were hurt in the accident, which happened while the former chemical company manager was visiting a client having problems with the dishwashing machine. For six to eight months, his overall vision was so bad his wife or son had to lead him around. But his right eye was less injured than his left and could provide stem cells for the transplant.

Jurkunas, who is also affiliated with Harvard Medical School, said Durst’s 2018 surgery was the culmination of almost two decades of research, “so we felt immense happiness and excitement to finally do it.” All patients in the study saw their cornea surfaces restored. Durst and another patient were then able to get transplants of artificial corneas, while two others reported much-improved vision with the stem cell transplant alone. A fifth patient didn’t get the procedure because the stem cells weren’t able to adequately expand.

At this point, Durst said the vision in his right eye is nearly perfect but the vision in his left eye is blurry; he’s scheduled for a different procedure in September to address that. Jurkunas estimates about 1,000 people in the U.S. per year could potentially benefit from this sort of stem cell transplant, which has also been studied in Japan.

“There’s definitely an unmet clinical need for this effort – there’s no question,” said Dr. Tueng Shen, an ophthalmology professor at the University of Washington who was not involved in the research. She added that doctors currently have no reliable source of cultivated limbal stem cells.

Researchers are finalizing the next phase of the clinical trial, which includes 15 patients. One is Nick Kharufeh, whose left eye was injured in 2020. He was watching fireworks being set off in the street when a spark hit his eyeball. Kharufeh moved from California to Boston to take part in the study, and the 26-year-old real estate agent can see well enough to fly a small plane.

Though he’s given up on plans of becoming a commercial pilot, “I still fly whenever I get back to California. I love it,” he said. “I’m just really thankful that they gave me the opportunity to be part of the trial because it’s really helped me out.” (AP)