Two patients suffering from the most common form of sight loss in the UK have successfully regained their reading vision after a groundbreaking clinical study.
A man in his early 80s and a woman in her early 60s received a new stem cell-based treatment for age-related macular degeneration (AMD), a condition which leads to a rapid loss of central vision.
It is the first time an engineered piece of tissue has been successfully used to treat people with sudden severe sight loss.
The study into AMD - a condition which affects more than 600,000 people in the UK - is a major milestone for the London Project to Cure Blindness.
Researchers believe it could lead to an 'off-the-shelf' treatment within five years.
The study, published in the journal Nature Biotechnology, was the result of a partnership between Moorfields Eye Hospital NHS Foundation Trust, the UCL Institute of Ophthalmology, and the National Institute for Health Research (NIHR).
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."
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."