Twelve children in the US have had their vision restored to normal after the lenses in their eyes had been removed because of cataracts.
Replacement lenses were regrown using stem cells, and eight months after surgery the lenses were the same as normal lenses.
In a separate research paper, scientists in Japan report also using stem cells in a tissue-engineering process that delivers sheets of corneal cells for transplant back onto the cornea after surgery.
The US group based at the University of California San Diego conducted lens replacement procedures on rabbits and on macaques before using the same procedure in 12 children, all under the age of two.
They all had cataracts and risked permanent damage to their eyes before treatment.
Healthy cornea
The Japanese research team based at Osaka University restored a healthy cornea in rabbits.
In all cases the recipients of the cells were also the donors, so the issue of rejection of transplanted or regrown tissue was not an issue.
This factor also made it possible to conduct an experimental procedure in children which has proved its worth, given the successful outcome.
Transparent lenses unclouded by cataracts were regenerated in the children in question within three months, “all without complication”, the authors said.
Both research reports were published on Wednesday evening by the journal Nature and were described as "remarkable accomplishments" by one expert in stem cell research.
The Japanese group were “ pushing limits in terms of what can be done in a laboratory dish”, said Dr Dusko Ilic, reader in Stem Cell Science at King’s College London.
Although this technology might become applicable at some future date, it is “currently falling short of being able to lead to first-in-human trials in the near future, due to costs and safety”, he said.
He was glowing, however, when it came to the group who treated the children. He described it as “one of the finest achievements in the field of regenerative medicine until now”, adding, “It is science at its best.”
