Neuroscientists at the University of Stanford School of Medicine have restored the sight to three mice and the procedure is being hailed as remarkable and a huge step toward the possibility of curing over 70 million people around the world of their blindness.
The scientists were able to repair the damaged optic nerves that connect the eyes to the brain. The researchers purposely destroyed the nerves in the mice so as to closely resemble the affects of glaucoma. Glaucoma is the second leading cause of blindness. While the scientists refused to say that they may have cured human blindness, they were extremely pleased with the results and hope that their research is just one more step toward curing blindness in humans.
While surgeons can cure and remove cataracts from human eyes, there is currently nothing that can be done for glaucoma. The research at Stanford has made it possible that there may, in the near future, be a cure for human glaucoma. Glaucoma causes extensive pressure and damage to the optic nerve to the point where it will no longer receive messages from the eye’s retinas.
There are around one million cells that connect the brain and the human eyes. Axons, long fiber like nerves, send messages from the eyes to several parts of the brain and back again. If damaged by glaucoma or some other affliction, the nerves and the cells can’t regenerate themselves. They are, effectively, destroyed forever leaving the person pretty much totally blind.
There is something known as the mTOR pathway that is important for sight but tends to degenerate with age and time. The researchers tried to figure a way to stimulate this pathway in an effort to restore sight to the mice. They thought if the could reinvigorate the pathway, it might help to actually regenerate the axons.
They treated the mice with gene therapy aimed at the mTOR pathway and also showed them rapid fast black and white images of a grid. Some were done separately while at other times both treatments were combined. After three weeks the scientists found that that axons had regenerated somewhat but when they covered up the good eye of a mouse and forced it to used the damaged one more, they found that the axons had regenerated themselves to where they were, once again, connecting with the proper areas of the brain.
While only about five percent of the the nerves were regenerated, the mice regained their sight to various strengths. The next step for the researchers is to figure out a way to regenerate more than five percent of the nerves.
PHOTO CREDIT: Pixabay