AUDIE CORNISH, HOST:
For the first time ever, scientists are reporting that human embryonic stem cells may be helping treat patients. In the medical journal The Lancet, researchers describe how the cells seem to help restore eyesight to some blind people.
NPR's Rob Stein has the details of the first study to demonstrate that embryonic stem cells could alleviate human suffering.
ROB STEIN, BYLINE: Human embryonic stem cells can be turned into any kind of cell in the body. So scientists have been hoping they could treat lots of diseases. But no one's done a careful study to find out if that's true until now. Steven Schwartz at UCLA tried using stem cells to help people suffering from two types of incurable eye diseases.
STEVEN SCHWARTZ: These represent the two leading causes of adult and juvenile blindness in the developed world.
STEIN: They're called age-related macular degeneration and Stargardt's macular dystrophy. They don't make people totally blind, but they destroy everything but peripheral vision.
SCHWARTZ: Whatever you're looking at is gone whether it's faces or reading or food on a plate or whether something's a step or a stripe. It's very, very difficult to perform activities of daily life that we, you know, don't even think about.
STEIN: Here's what they did. Schwartz and his colleagues took human embryonic stem cells and turned them into the kinds of cells that are killed by these diseases. Then, they infused tens of thousands of these cells into the retinas of 18 patients.
SCHWARTZ: What we did is put them into patients who have a disease where those particular cells are dying. And we replaced those dying tissues with new tissue that's derived from these stem cells. In a way, it's a retinal transplant.
STEIN: The study was designed mostly just to see if doing this was safe. There were big worries the whole thing could backfire. The cells could destroy whatever vision was left or turn into horrible tumors in the volunteer's eyes. So Schwartz picked patients whose eyes were so far gone that they weren't risking losing any vision. But that meant there was little hope the cells could help patients either.
SCHWARTZ: We did not expect to help these patient. And they did not expect to be helped.
STEIN: It's been nearly two years since the first patients got the cells. And so far, there are no signs of any safety problems. And to everyone's surprise, a lot of the patients did start to see better. Ten of the 18 patients can see a lot better. One got worse, but the other seven either got better or didn't lose any more vision.
SCHWARTZ: These are patients that didn't see better for 30 years, and all of a sudden, they're seeing better. It's amazing.
STEIN: There's a graphic artist who could suddenly make out the woodwork carved on a piece of furniture in her bedroom, an international consultant who eventually regained the ability to walk through busy airports without help, and an elderly rancher who's riding his horse again.
SCHWARTZ: He couldn't see things like barbed wire fence or whether in the distance a stray cow was under tree. And six months after the transplant, he's back to running his cattle again. And he can, in fact, see a snake on the ground or see a barbed wire fence from his horse or tell whether or not a distant shadow is a cow or something else. And so it's made a huge difference for him in his life.
STEIN: Isabella Bewkes (ph) of Santa Rosa, California has been legally blind for more than 40 years. But within weeks of getting the cells, she started to see better. She could make out the cursor on her computer screen, the color of her clothes. Today, she can hike the hills near her house all by herself.
ISABELLA BEWKES: The improvement, I mean from where I was coming, is just - it's very, very significant for me. I think it's fantastic. I just think to be part of groundbreaking research work is amazing.
STEIN: This research is controversial. Embryos are destroyed to get the cells. Some people think that's immoral. For his part, Schwartz says he's just trying to help blind people see better. But he cautions that this work is still at a very early stage. He's only treated a few dozen patients altogether so far and followed them for just 22 months.
SCHWARTZ: I don't want to increase suffering by creating expectations that can't be met.
STEIN: Other researchers agree that these findings need to be considered preliminary, but they say the results so far are really promising. Anthony Atala is at Wake Forest University.
ANTHONY ATALA: It's really a very important paper because it really does show for the very first time that patients can in fact benefit from the therapy that allows you to say OK, now these cells have been used for patients who have blindness. Maybe we can also use these cells for many other conditions as well, including heart disease and lung disease and other medical conditions.
STEIN: Schwartz has continued treating more blind patients using bigger doses of cells and trying it on patients who haven't lost as much vision to see if that works even better. He's also expanded his study to Boston, Miami, Philadelphia and London. Rob Stein, NPR News. Transcript provided by NPR, Copyright NPR.