Today, 285 million people are visually impaired with nearly 40 million completely blind, according to World Health Organization statistics. The three most common causes of blindness are cataracts, glaucoma and age-related macular degeneration. But it is only now that scientists have been making real progress in finding a potential cure for blindness with the latest accomplishment being the restoration of sight in blind mice.
Researchers at the University of Oxford have stated that their studies are very similar to how a blind person might be treated. They used mice who were completely unable to tell the difference between light and dark as they lacked light-sensing photoreceptor cells in their retinas. The mice were literaly injected with ‘precursor’ cells that were designed to develop into a retina – which is exactly what happened two weeks after the injections. The research team presented their findings in the Proceedings of the National Academy of Sciences Journal.
Although there have been studies that have achieved similar feats, they involved mice which had partially degenerated retinas. In the case of the team at Oxford, they managed to reconstruct the entire light-sensitive layer representing a breakthrough in the field.
The results were too visible in a pupil constriction test in which 10 of the 12 mice that received the cell transplant demonstrated pupil constriction in response to the light highlighting that information was being sent from the optic nerve to the brain.
Technologies currently being examined for curing blindness include the injection of stem cells, gene therapy and the installation of electronic prosthetic devices that stimulate blind neurons. It seems the most promising steps have been taken in the field of stem cell research as this breakthrough comes along with another recent discovery made that cells in the front part of the eye can replace diseased ones in the back of the eye.
However, much more research is required as these tests aren’t sufficient enough to determine the true quality of the vision that has been restored. Professor MacLaren, who led the research at Oxford states clearly that they would like to use induced pluripotent stem cells or iPS cells. These are the stem cells which have been cultivated from the patient himself, like skin or blood cells which can then be directed to create precursors of the retina cells.
Indeed it would seem the race to cure blindness has only just begun as singer Art Garfunkel alongside other individuals, has chipped in by putting up a $2 million reward for researchers who manage to ‘cure’ blindness by 2020.
World Health Organization
National Academy of Sciences Journal