Medics at Moorfields Eye Hospital in London have successfully repaired vision in two patients suffering from age-related macular degeneration (AMD) using stem cells, raising hopes that similar sight-restoring treatments will be available “off-the-shelf” within five years. The results have been published in the journal Nature Biotechnology.
First of all, a little bit of background on AMD. There are two types: wet and dry. Both of the patients here had “wet” AMD, which is caused by abnormal blood vessels that leak fluid or blood onto the macula. The macula is an important part of the eye's retina made up of light-sensing rod and cone cells and a nourishing layer of cells called the retinal pigment epithelium. In contrast, "dry” macular degeneration is less serious, more common, and occurs when deposits build up beneath the macula and cause it to deteriorate.
The disease is the number one cause of blindness in the UK, affecting more than 600,000 Brits. In the US, an estimated 11 million people live with some kind of AMD – a number that is predicted to double by 2050, largely thanks to an aging population.
“As you get older, parts of you stop working,” Lyndon da Cruz, a consultant retinal surgeon involved in the research, told BBC News. “[F]or the first time we've been able to take a cell and make it into a specific part of the eye that's failing and put it back in the eye and get vision back."
He was, however, quick to point out that treatment is not quite a complete fix. While the patients’ vision improved dramatically, neither attained the quality of vision they had before their disease took hold.
The vision-restoring treatment involved stem cells, which very conveniently can be converted into any type of cell in the human body. In this particular case, embryonic stem cells were used to form the kind of cells found in the retinal pigment epithelium. Medics then performed two-hour-long operations on the patients that involved inserting a one-cell-thick patch under the cones and rods at the back of the affected eye.
A year later, the first patient’s reading speed had jumped from 1.7 words per minute to 82.8 words per minute. Meanwhile, the second patient had improved from 0 words per minute to 47.8 words per minute.
"It's brilliant what the team have done and I feel so lucky to have been given my sight back," 86-year-old Douglas Waters told BBC News.
As of yet, there have been no serious complications though there are concerns that certain stem cell treatments can raise the risk of cancer.
So far, so promising. The medics even believe it can be used to treat dry AMD but more studies are needed to confirm both this and the success of treatment in patients with wet AMD. Already, eight more patients are due to take part in the current clinical trial.
"This study represents real progress in regenerative medicine," Pete Coffey of University College London's Institute of Ophthalmology told BBC News. "We hope this will lead to an affordable 'off-the-shelf' therapy that could be made available to NHS patients within the next five years."