Graduated stem cell therapy to repair severely damaged cornea and improve vision

The next boundary of stem cell transplantation may involve the eyes. In today's study, scientists report that an experimental therapy has caused incurable harm to the cornea in people.

Mass Eye and Ear researchers led the study, a phase I/II clinical trial of 14 patients. In most cases, this therapy is a transplantation of stem cells transplanted from another healthy eye of the person to safely restore people's severely damaged corneal surface, which can often improve their vision as well. The researchers say the findings could lead to novel treatments for eye damage that do not respond to traditional choices.

The cornea is the most transparent eye of the eye, which can both protect it and be clearly seen by focusing the light on the retina. When people's cornea is scarred by severe injuries or infections, doctors can often treat it by transplanting healthy corneal tissue from a donor, also known as corneal grafts.

But sometimes, the damage is so widespread that it depletes a large but limited supply of corneal epithelial cells, i.e. stem cells that supplement cells on the corneal surface. This depletion is called hydronegative stem cell deficiency, which permanently damages the surface of people’s corneals, which means that typical corneal grafts cannot be a lasting treatment (without stem cells, donated corneas will eventually worsen).

“When people suffer from corneal stem cell deficiency, it's a very devastating condition, they may have real white corneas without vision. And there's a lot of pain and discomfort. There's actually no good way to treat this. cornea Service in the eyes of the public, tell Gizmodo.

Various research teams have been working on solving these difficult cases for years, and Jurkunas and her team now believe they have taken an important step in doing so. They have developed a technology to safely collect and then plant healthy stem cells from a person's uninjured cornea. These cells are called cultivated autologous epithelial cells (CALECs) that are concentrated into cell tissue grafts and then transplanted to the injured cornea of ​​the person.

The team's early work in four patients found that CALEC grafts can be safe and effective at least in the short term. In a new study published Tuesday in Nature Communications, the team collected data from 14 patients to 18 months after surgery.

Overall, 92% of patients responded at least partially to CALEC after one and a half years, and 77% of them experienced complete recovery of the corneal surface (three patients also received a second graft, and 1 case had a complete response thereafter). All patients also had at least improved vision. And the transplant appears to be safe tolerant, with no serious reports of adverse events related to the surgery (a person did experience a bacterial infection a few months later, although this is attributed to the use of chronic contact lenses).

“The symptoms of many of them have changed dramatically. These are really serious injuries and there is no current treatment. But now they are able to play a role,” Jukunas said. “I had a patient who told me, 'I actually recovered my life.'”

Of course, this process is still experimental. Many patients who respond to CALEC grafts may also require additional corneal grafts to substantially improve. But according to scientists, this is the first stem cell therapy of its kind in the United States that can be successfully used in people with corneal blindness.

“I think this is usually a very big stepping stone for stem cell therapy. Again, we don't use stem cells of embryonic cells. These are adult stem cells that already exist in our bodies, but we are able to use them and create products to treat that person's body with our own stem cells,” Jurkunas said.

Researchers are still trying to conduct larger clinical trials that can be performed in different eyes, so there is currently no experimental procedures for any patient. They also hope to further improve the technology, such as allowing other donors to culture and transplant stem cells from other donors, which will open treatment to people with two types of damaged corneas. If the team’s work continues to show hope, CALEC and similar treatments are likely to become the new standard of care for these once irreversible cases.