A revolutionary medical technique that harnesses the power of stem cell therapy has restored the vision of two patients.
A man in his 80s and women in her 60s suffered from age-related macular degeneration - the most common form of blindness - and were unable to read even with glasses.
However, they regained their vision and could read normally after a team of British doctors inserted a patch of stem cells into their retinas.
The groundbreaking trial, conducted at Moorfields Eye Hospital, offers hope of a cure for the condition, which strikes 600,000 adults in the UK and two million in the US.
It is the first time an engineered piece of tissue has been successfully used to treat people with sudden severe sight loss.
Researchers believe it could lead to an 'off-the-shelf' treatment within five years and could become as commonplace as cataract surgery.
Scientists at University College London created the procedure with the help of experts at the National Institute for Health Research.
How is the procedure carried out?
The stem cell procedure, which can take as little as 45 minutes, is carried out under local anaesthetic.
It involves taking a single embryonic stem cell and growing it into a 6mm patch of 100,000 retinal pigment cells.
That patch is then rolled into a thin tube, which is injected through a tiny slit in the eye.
Once unfurled, it is placed behind the retina where scientists claim it replaces the faulty cells.
The new findings, which saw the two patients monitored for 12 months, are a major milestone for the London Project to Cure Blindness.
The movement was established ten years ago with the aim of curing vision loss in patients with age-related macular degeneration.
The study was published in the journal Nature Biotechnology.
Professor Lyndon da Cruz, consultant ophthalmologist at Moorfields Eye Hospital NHS Foundation Trust said: 'The results suggest that this new therapeutic approach is safe and provides good visual outcomes.
'The patients who received the treatment had very severe AMD, and their improved vision will go some way to enhance their quality of life.
'We recognise that this is a small group of patients, but we hope that what we have learned from this study will benefit many more in the future.'
How was the study carried out?
The study investigated whether the diseased cells at the back of the patients' affected eye could be replenished using a stem cell patch.
A specially engineered surgical tool was used to insert the patch under the retina in the eye of each patient in an operation lasting one to two hours.
The patients - who went from not being able to read at all, even with glasses, to reading 60-80 words per minute with normal reading glasses - were monitored for 12 months and reported improvements to their vision.
Professor Pete Coffey from the UCL Institute of Ophthalmology said: 'This study represents real progress in regenerative medicine and opens the door on new treatment options for people with age-related macular degeneration.
"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.'