Stem cell injection has potential to halt sight loss in early AMD

A team of US researchers has shown that stem cell transplants can prevent sight loss from age-related macular degeneration (AMD). A single injection of stem cells into the eye was able to stop the condition from progressing in rats with early AMD-like symptoms.

AMD is one of the leading causes of sight loss in the UK, affecting around 0.5 million people. In AMD, light-sensitive cells in the macula – the part of the eye used for detailed vision – become damaged and eventually die. There is currently no treatment to stop ‘dry’ AMD (the most common form of AMD) from progressing.

One way to protect vision could be to bring in healthy cells to do the job of cells lost to AMD. In the current study, researchers took adult human skin cells and converted them into a type of stem cell that can become nerve cells.

Results published in the journal Stem Cells showed that after these ‘induced neural progenitor cells’ were injected into the rat eye, they formed a protective layer that prevented further AMD-related damage.

Long-lasting effects

Treated eyes had more photoreceptors and more electrical activity in response to light than untreated eyes and there was no further sight loss. The effects lasted for 130 days in the rats – roughly 16 years in human terms.

“This is an early, pre-clinical study and there is still much to do in terms of safety and effectiveness before the injections could be tested in humans,” said Dr Dolores M Conroy, Director of Research at Fight for Sight.

“However, cell replacement therapy for AMD using a readily available source of stem cells is an exciting approach that could slow or perhaps even reverse sight loss in the crucial early stages, long before people have lost the ability to read or recognise faces. This is the number one priority identified by people affected by AMD during the James Lind Alliance Sight Loss and Vision Priority Setting Partnership.”