Stem cells hold promise for ending blindness

Stem cells hold promise for ending blindness
By DAVID TEMPLETON Pittsburgh Post-Gazette
The cure was so dramatic that it surprised even the researchers.
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They had injected human adult stem cells into the corneas of mice and,
in due time, the scarring and cloudiness that cause corneal blindness
disappeared.

But the results were more than met the eye.

Repairing corneas with adult stem cells, which already exist in the
human eye, signals an advance in stem-cell research that could apply
bodywide.

As such, research led by James Funderburgh, an associate professor in
the University of Pittsburgh School of Medicine's Department of
Ophthalmology, is clarifying more than mice corneas. It also points to a
day when one's own stem cells can be used to repair one's injuries and
cure one's diseases.

"What they are doing is revolutionary stuff," said Dr. Ivan Schwab,
professor of ophthalmology at the University of California, Davis, who
isn't involved with the research.

Funderburgh and first author Yiqin Du, of Pitt – along with researchers
from Case Western Reserve University and the universities of South
Florida and Cincinnati – published results of their research in Stem
Cells journal recently.

"This proves that these stem cells can be used to treat scars and
abnormal corneas," Schwab said. "This also has implications for other
disease."

According to the study, Funderburgh and his team used stem cells – basic
cells that can turn into specialized cell types – that already exist in
the stroma, or fibrous part of the eye. These cells were cloned, then
injected en masse into damaged cornea of mice.

In the cornea, the cells activated to transform into corneal cells that
reorganized the tissue fibers and produced a smooth, transparent cornea.

The process was more difficult than it might appear. It required a
method to inject cells into the thin corneas of mice and track the
progress with dyes. It also required documenting eye improvements in
mice.

As Funderburgh wryly noted, "It's hard to have a mouse read an eye
chart."

But rodent corneas were restored to perfection. Funderburgh said it
shows potential to cure corneal blindness "with a simple injection."

The success with mice, he said, "is a start, but we have a ways to go."

Repeating the process in humans remains years away. The human cornea is
thicker and more complex than mouse corneas. But tests done on human
eyes from an eye bank that couldn't be used for transplantation show
that the technique could be used on human eyes.

In the United States, cornea transplantation is the primary treatment
for damaged corneas that cause vision problems and blindness. About
40,000 cornea transplants are done annually in the United States.

But transplants require donated corneas and delicate surgery not
available in many parts of the world. Transplants also can lead to
rejection. Even good transplants can result in less than perfect vision.

So the stem-cell procedure could offer a cheaper procedure with superior
results.

"The stem-cell therapy would be much simpler and could be an outpatient
therapy – if it works," Funderburgh said.

David Templeton can be reached at dtempleton@post-gazette.com.
Distributed by Scripps Howard News Service.

Mrs. Kathy M
Visual Impairments Specialist