Doctors in the United Kingdom have restored the eyesight of two patients suffering from a common form of vision loss by treating them with stem cells.
The two patients, an 86-year-old man and a woman in her sixties, both suffered from age-related macular degeneration, the most common form of sight loss in the developed world, and one that affects around 1,000,000 Canadians, according to CNIB estimates.
The two patients had the less-common “wet” form of the disease, which is caused by abnormal blood vessels leaking fluid into a portion of the retina. AMD commonly causes problems with central vision, such as blurriness, dark areas and distortion that make activities like reading and driving difficult, if not impossible. About 10 per cent of people with AMD have the wet form.
The researchers, who published their results in the journal Nature Biotechnology, inserted a patch of stem cells surgically into the patients’ eyes, to replenish the diseased retinal cells, according to a press release from the Moorfields Eye Hospital, where the trial took place. They then monitored the patients for 12 months.
According to the release, both patients went from being unable to read at all before the treatment to being able to read 60-80 words per minute using normal reading glasses.
“In the months before the operation my sight was really poor and I couldn’t see anything out of my right eye. I was struggling to see things clearly, even when up-close,” said Douglas Waters, one of the patients who received the experimental procedure, according to the press release. “After the surgery, my eyesight improved to the point where I can now read the newspaper and help my wife out with the gardening.”
Dr. Varun Chaudhary, a retinal surgeon and chief of ophthalmology at the Hamilton Regional Eye Institute, said that this surgical procedure could be a big improvement on current treatments for wet AMD.
Right now, the “gold standard” involves giving the patient an injection in their eye every month or two for the rest of their lives, he said. This surgical procedure leads to a similar improvement in vision, but only has to be done once – which would be much better for patients and doctors, he said.
However, he would want to see the long-term results – whether these patients maintain their eyesight over the next few years. “Patients don’t live for three months or six months, they live for years,” he said.
Dr. Kevin Gregory-Evans, a professor of ophthalmology and visual sciences at the University of British Columbia, said that the trial is an important step in research on AMD, but doesn’t regard it as a “huge breakthrough.”
He imagines that eventual treatments for AMD will involve tailor-made therapies to address the particular problem that each individual patient has.
Chaudhary finds the way that the researchers inserted the stem cells to be very interesting and potentially applicable to other retinal diseases. Previous methods that injected stem cells into the retina had problems with cell survival and didn’t have the same kind of positive results, he said.
“Delivering cells in the retina would have implications for other genetic eye diseases for which we currently have no good therapeutic option.”
Although the researchers recognize that a trial involving just two subjects is a very small group and hard to draw conclusions from, they are hopeful that their procedure could lead to better treatment for people with AMD – perhaps within five years.
Gregory-Evans is less optimistic. “I think it’s important to emphasize that stem cell therapy for macular degeneration is still at a very experimental stage.”
He thinks it will be at least 10 years before this kind of therapy is widely available. Chaudhary also thinks that it will take time – the procedure will have to go through rigorous safety checks and be tested on a larger population before it starts to be approved for general use, he said.