LOS ANGELES – Two legally blind women appeared to gain some vision after receiving an experimental treatment using embryonic stem cells, scientists reported Monday.
While 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.
“This 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.
Last 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 other had a rare disorder known as Stargardt disease that causes serious vision loss.
After four months, both showed some improvement in reading progressively smaller letters on an eye chart. The Stargardt patient went from seeing no letters at all to being able to read five of the largest letters.
However, 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.
“One must be very careful not to overinterpret the visual benefit,” said Vanderbilt University retina specialist Dr. Paul Sternberg, the president-elect of the American Academy of Ophthalmology.
Lancet published the findings online Monday.