Scientists have engineered a biocompatible, light-sensing protein, which they’ve used to restore daylight vision in mice blinded by an inherited and degenerative eye disease called retinitis pigmentosa.
Millions of people around the world suffer from retinitis pigmentosa and other age-related forms of blindness, such as macular degeneration. These occur when photoreceptor cells in our retinas, which convert light into signals that our brains can decode as vision, stop functioning. Despite this loss of function, the pathways for vision keep working. This includes another layer of fully functioning cells in the inner retina, known as ON-bipolar cells. The problem is, these cells can’t sense light.
A promising new treatment known as optogenetics uses a modified virus to introduce genes that encode light-responsive proteins inside the survivor cells. The aim is to turn them into pseudo photoreceptors and, ultimately, restore vision. But optogenetic treatments face major hurdles before they can find clinical applications, because they tend to require proteins that only respond to unnaturally high and potentially harmful light intensities, and they rely on foreign signalling mechanism to activate the target cell.
But now, researchers from the University of Berne in Switzerland, say they’ve engineered proteins that are more compatible with cells in the retina, activating them using natural triggers, which could bring optogenetic therapies one step closer to human trials and medical applications. “The new therapy can potentially restore sight in patients suffering from any kind of photoreceptor degeneration… [including] those suffering from severe forms of age-related macular degeneration, a very common disease that affects to some degree about one in every 10 people over the age of 65,” Sonja Kleinlogel, who leads the university’s Optogenetics Lab, said in a press release. Source: Scientists figure out how to restore vision in blind mice – ScienceAlert