Doctors are reversing blindness for the first time

There will soon be a cure for blindness?

For the first time, researchers have succeeded in restoring vision in blind mice. They turned maintenance neurons into sticks and cones that represent the light-sensitive structures of the eyes.

The scientists at the National Institutes of Health changed so-called maintenance neurons in their eyes so that blind mice could see again.

Many people in the world are blind

Blindness is a disease that affects many people around the world. Almost three million Americans see bad and another 1.3 million Americans are completely blind, say the experts. The number of people who suffer from macular degeneration in their old age and then go blind will double by 2050 and reach about 22 million, the scientists suspect.

Mice recovered their eyesight

However, if the newly developed treatment proves to be successful in people, many of those affected could regain their eyesight. The scientists used a gene injection to transform cells that help make the retina form photoreceptors that restore vision in blind mice.

Why do we see worse and worse in old age??

Cells die constantly and are then replaced by new cells, but as people get older, the rate at which cells die off and the rate slows down, say the experts. Neurons are not particularly good at regeneration, and they include photosensitive photoreceptor cells. This group of highly specialized neurons in the retina, which wrap around the fundus, consists mainly of rods and cones.

What is the task of chopsticks and cones?

Chopsticks capture images in low light, while cones are sensitive to fine details and colors. Rods allow you to see in low light, but they can also help preserve the photoreceptors that are important for color vision and high visual acuity, study author Dr. Thomas Greenwell of the National Institutes of Health in a press release. Cones tend to die in late-stage eye diseases. If rods could be regenerated from within the eye, this would be a strategy for treating eye diseases affecting the photoreceptors.

Strengths and weaknesses of the human eye

The human eye is very good at seeing fairly large distances in detail and in a large color palette, but our peripheral vision and night vision are not nearly as good as, say, a cat. Also, our eyes can not regenerate as well as, for example, the eyes of zebrafish. Even if the eye is severely injured several times, a zebrafish remains the view, while the rods and cones of the people die just in old age. The zebrafish has the advantage here that the so-called Müller glia cells in his eyes, which normally do not respond to light, can actually be converted into photoreceptors when needed.

Mammals can not convert glial cells into photoreceptors

However, mammalian glial cells do not have the same formability, and even if they had the same mechanism that induces transformation in the eye of the fish, it would only be triggered by injury, making treatment difficult for humans. Attempts to regenerate the retina to restore a person's vision are counterproductive from a practical point of view. First, to injure the retina to activate the Müller glia cells does not seem like a perfect solution, study author Dr. Bo Chen from the Icahn School of Medicine, Mount Sinai, New York.

Gene injection instructed glial cells to divide

The scientists tried to use gene therapy to program the so-called switch function in the glial cells of blind mice, without first injuring them. The gene injection instructed the glial cells to divide, the beginning of the regenerative process, explain the researchers. After a few weeks, they gave the mice another eye injection, which caused the new cells to become chopsticks instead of glial cells. The new, transformed cells looked like chopsticks, they also communicate like rods with other cells in the retina, explain the authors.

Experiments on people in the near future?

Although the mice were born without chopsticks, they could see through the procedure. But just because the rods work does not necessarily mean that the mice have a fully functional view, scientists say. Further research by the researchers is now to determine how the mice behave in a labyrinth to analyze whether all right cognitive connections of the re-sighted mice work. If so, scientists want to start making human glial cells into chopsticks in the lab. (As)