The day when scientists can reverse blindness has come a little closer, thanks to a discovery made at Moorfields Eye Hospital and University College London in the UK.
An animal study, published in the journal Nature Biotechnology showed that photoreceptors, the cells in the retina that react to light and convert it into an electrical signal, which can be sent to the brain, can be repaired using stem cells.
Photoreceptors can die off in some causes of blindness such as Stargardt’s disease and age-related macular degeneration.
The scientists used a new technique to build retinas in the laboratory. Thousands of stem cells were collected and primed to transform into photoreceptors, then injected into the eyes of blind mice.
About 1,000 cells of 200,000 transplanted hooked up with the rest of the eye and
began to function.
Lead researcher Professor Robin Ali told mivision: “Our recent study paves the way to develop methods to transplant photoreceptors derived from human embryonic stem cells.
“We have focused to date on rod photoreceptor transplantation but are now developing ways to transplant cones with the aim of developing a clinical trial for AMD. We anticipate that it will take at least five years before we might be ready to start such a trial,” he said.
In an interview with BBC, Prof. Chris Mason, from University College London, cautioned that the number of cells that succeeded in hooking up with the architecture of the retina were low. “I think they have made a major step forward here, but the efficiency is still too low for clinical uses.
“At the moment the numbers are tiny and it will take quite a bit of work to get the numbers up and then the next question is ‘Can you do it in man?’
“But I think it is a significant breakthrough which may lead to cell therapies and will
give a much expanded knowledge on how to cure blindness.”
Dr. Marcelo Rivolta, from the University of Sheffield, said the study was a “huge leap” forward for treating blindness and could have implications across stem cell research.