WEDNESDAY, Aug. 25 (HealthDay News) -- Swedish scientists report
that they've successfully implanted "biosynthetic" corneas in 10
patients, potentially paving the way for more accessible treatment
for those with cornea-related vision problems.
"The patients' own cells and nerves grew back, and there was an overall improvement in vision," said study co-author May Griffith.
Currently, some cornea patients get transplanted corneas from
donors who have died. "Human donor corneas work very well,"
Griffith said. "However, there is a shortage of good quality
corneas that can be used for transplantation."
The shortage means trouble for many of those whose corneas --
the clear surface at the front of the eye -- have been injured or
damaged by illness. An estimated 5 million people in the world have
an eye disease called trachoma that affects the cornea, and another
1.5 million to 2 million are thought to have developed
cornea-related blindness through other diseases or trauma.
For more than a century, doctors have considered transplantation
of corneal tissue from deceased donors to be the best treatment,
the study authors wrote. Artificial corneas are another option, but
they're difficult to implant into the eye and can cause side
effects, the researchers said.
In the new study, researchers tested corneal implants that are
"biosynthetic," meaning they're created with the help of living
tissues. In this case, the corneas are produced with the help of
human collagen -- a kind of protein -- that's grown in yeast. The
mock corneas were then placed into the eyes of 10 patients after
the diseased corneas were removed.
"We were pleasantly surprised that in six patients, vision improved from about 20/400 to 20/100, meaning that these patients could see objects four times farther away than before the operation," said Griffith, director of the Integrative Regenerative Medicine Center at Linkoping University in Sweden.
The researchers went one step further and gave contact lenses to
the patients. With the lenses in place, they all had improved
vision, Griffith said.
Why didn't they all get better vision immediately without the
contact lenses? "We believe that sutures used in this study
resulted in roughness on the surface," Griffith said. "The contact
lenses compensated for the surface roughness, resulting in improved
vision. We will use less disruptive sutures in our next clinical
study, and this should correct this problem."
As for side effects, Griffith said the patients didn't report
any pain or discomfort, and there were no signs that their bodies
tried to reject the corneas, a risk that people face when they get
As for cost, Griffith said the biosynthetic corneas "in theory"
should be cheaper than donated corneas. Griffith said a German
study recently found that donated corneas cost about $2,500.
The next step in research, Griffith said, is to create a "new
generation" of cornea implants and test them on a wider variety of
The study appears in the Aug. 25 issue of
Science Translational Medicine.
Dr. Mark J. Mannis, chair of the Department of Ophthalmology and
Vision Science at the University of California, Davis Eye Center,
said the findings in the study appear to be valid. "This is true
cutting-edge work and brings an exciting new option to the
repertoire of corneal transplant surgeons," he said.
For more about
corneal transplants, try the U.S. National Library of Medicine.
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