Recent research reported in Stem Cells Translational Medicine shows that cells removed from dead men’s (or indeed women’s) eyes may hold the answer to the blind regaining at least partial sight.
When scientists at the University College London (UCL) removed specific eye cells from dead human donors and injected them into blind rats, the rats showed marked improvement in their vision.
Whilst this remarkable approach offers hope for blind people, the research team from the Institute of Ophthalmology at UCL don’t believe that it could restore complete vision, sufficient to read a book. But trials in humans are expected to start in the next three years to assess effectiveness.
The use of donated corneas is already common to improve eyesight in appropriate patients, but the UCL team focused their investigations on Muller glia cells which are found at the back of the human eye. These cells possess adult stem cell characteristics and can change into more specialised cells.
By careful coaxing in the laboratory, the Muller glia cells from the dead donors were transformed into rod cells, which are photo receptive cells found in the retina.
These were then injected into the eyes of totally blind rats. By scanning the rodents’ brains, it was found that the treatment resulted in 50% improvement in electrical signals between the brain and eyes.
Professor Astrid Limb from the UCL team believes that this procedure could make a real difference to blind people. Even if they couldn’t read or watch TV, they would be able to visualise objects in a room and even make a cup of tea, improving the quality of their life significantly.
The cells may also have uses in degenerative eye diseases such as retinitis pigmentosa or macular degeneration.
Muller glia cells are much easier to source compared to stem cells taken from human embryos, which are already in use in human trials, and without the associated ethical debate. In addition Muller glia cells take only a week to prepare as opposed to several months for the embryonic stem cells.
However the UCL researchers point out that Muller glia cells have antigens which could trigger the recipient’s body to reject the donated cells – rather like the rejection of a transplanted organ.
Now work needs to begin to prepare the cells to a clinical standard suitable for human trials.
Dr Paul Colville-Nash of the Medical Research Council believes that these results support further investigation into the use of Muller glia cells in treating eyesight disorders. Without knowing which approach will give positive results in humans, Colville-Nash emphasises that all avenues open to researchers should be progressed in the quest to cure loss of sight.