ANGELES (AP)—Two legally blind women appeared to gain some vision after
receiving an experimental treatment using embryonic stem cells,
scientists reported Monday.
embryonic stem cells were first isolated more than a decade ago, most
of the research has been done in lab animals. The new results come from
the first tests in humans for a vision problem. Researchers caution the
work is still very preliminary.
study provides reason for encouragement, but plans to now get such a
treatment would be premature,” said stem cell expert Paul Knoepfler of
the University of California, Davis, who had no role in the research.
summer, each patient was injected in one eye with cells derived from
embryonic stem cells at the University of California, Los Angeles. One
patient had the “dry” form of age-related macular degeneration, the most
common cause of blindness. The other had a rare disorder known as
Stargardt disease that causes serious vision loss. There’s no cure for
either eye problem.
four months, both showed some improvement in reading progressively
smaller letters on an eye chart. The Stargardt patient, a graphic artist
in Los Angeles, went from seeing no letters at all to being able to
read five of the largest letters.
experts said the improvement of the macular degeneration patient might
be mostly psychological, because the vision in her untreated eye
appeared to get better too.
Both patients remain legally blind despite their improvements, said experts not connected with the study.
must be very careful not to overinterpret the visual benefit,” said
Vanderbilt University retina specialist Dr. Paul Sternberg, who is also
the president-elect of the American Academy of Ophthalmology.
findings were published online Monday by the journal Lancet. This early
test was meant to study whether the stem cell therapy was safe in
people and not whether it would improve vision.
at UCLA and Advanced Cell Technology, which funded the work, said they
were pleased that there have been no signs of rejection or abnormal
growth months after the procedure.
stem cells can transform into any cell of the body. Scientists are
hoping to harness embryonic stem cells to create a variety of
replacement tissues for transplant, but their use has been controversial
because human embryos have to be destroyed to harvest the cells.
latest news comes two months after Geron Corp. halted its stem
cell-based experiment for spinal cord injuries, saying it planned to
focus instead on two experimental cancer drugs.
ACT is pushing ahead with its blindness study. The company said Monday
that surgeons in London injected a patient with Stargardt disease last
SOURCE: The Associated Press