Scientists Helps Mice Restore Lost Vision, Could It Work For Blind People, Too?

In a major breakthrough, a group of scientists have regenerated parts of damaged optic nerves in blind mice suffering from glaucoma like condition to help them get their eyesight back again partially.

The research team, led by Andrew Huberman from Stanford University, have published their study in the journal Nature Neuroscience. For the purpose of the study, the researchers purposely destroyed the optic nerve in one eye of mice to resemble the effects of glaucoma. Glaucoma, which is the second-leading cause of blindness in the world, currently affects about 70 million people worldwide. The eye condition results from excessive pressure on the optic nerves, which are responsible for conveying visual information from the eye to the brain.

The long, thread-like arms of the nerve cells present in the optic nerve, called the axons, connect the eyes to more than two dozen regions of the brain. Once axons in the brain gets damaged, they do not regenerate themselves and may result in permanent vision loss. However, axons present outside the central nervous system have the ability to regenerate.

During the study, the research team treated mice by either molecular reactivation or exposing them to high-contrast visual stimulation. After three weeks, they found that while neither approach alone was successful in re-establishing the link between brain and eye, a combination of gene therapy and visual stimulation did the work, reported Time.

"We saw enormous synergistic effect," said Huberman, reported Live Science. "There was a 500-fold increase in the distance and speed that the retinal ganglion cell axons grew. And in the same period of time that normally they wouldn't grow at all, they managed to grow all the way back into the brain."

The researchers claimed that while the mice had their vision restored partially, they failed other vision tests which required finer visual capabilities. Huberman added that only less than 5 percent of neurons regenerated, so, they need to check out for ways to get more cells to regenerate.

"I want to see something positive in humans within five years," he said.