Scientists have taken a key step toward the development of what could be a breakthrough treatment for corneal blindness, a condition that affects millions of people around the world.
The scientists showed that stem cells obtained from the dental pulp of extracted teeth can be turned into the specialized cells that keep corneas healthy and free of blinding scars caused by illness or injury--and that these cells could safely be injected into the corneas of mice.
The approach anticipates a treatment with clear advantages over the usual method of treating corneal blindness, in which a patient's scarred corneas are replaced with healthy tissue from donor corneas. In some cases, the patient's body rejects the transplanted tissue, and donor corneas are in short supply in certain parts of the world, including Africa and Asia.
"Our work is promising because using the patient's own cells for treatment could help avoid these problems," Dr. James L. Funderburgh, professor of ophthalmology at the University of Pittsburgh School of Medicine and the senior author of a new paper describing the research, said in a written statement.
For the research, a team led by Dr. Fatima Syed-Picard, a post-doctoral fellow in the school's department of ophthalmology, took cells from the pulp of extracted wisdom teeth and used chemical processing to convert them into the specialized corneal cells. Then the scientists injected these so-called keratocytes into the corneas of healthy mice, where they integrated with the existing tissue with no sign of rejection even after several weeks.
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Close-up photo of mouse eye showing injected cells (green).
How would the treatment be used in human patients?
"We are thinking that in the future people may 'bank' their extracted wisdom teeth or the cells from those teeth," Funderburgh told The Huffington Post in an email. "For someone who did not do that it is possible to extract dental pulp with a root canal procedure, but this is still hypothetical. In the worst-case scenario, someone might consider having a tooth extracted to provide cells for this procedure."
Last year more than 70,000 corneal transplants were performed in the U.S., Kevin Corcoran, president and CEO of the Washington, D.C.-based Eye Bank Association of America (EBAA), told the Pittsburgh Tribune-Review.
"There's a lot of exciting research being done in the area of [corneal] transplant, and EBAA is interested in any outcome that can help restore sight to the blind or visually impaired," said Corcoran, who was unfamiliar with the Pitt research.
Syed-Picard stressed the preliminary nature of the research and said it would probably take a few years before human testing could begin. The next step, she said, would be to conduct a similar set of experiments in rabbits.
The paper was published online Feb. 23, 2015 in the journal Stem Cells Translational Medicine.