The retina a light-sensitive layer located backside of the eye covers about 65 percent of its interior surface. It consists of millions of light-sensitive photoreceptors cells that convert incident light into signals that carried to the brain by the optic nerve. But, sometimes a mutation in a cell can cause retinal degeneration. This makes photoreceptor cells dead and retinal neurons around them unaffected as well.
To treat this unaffection, earlier research has looked at treating retinal pigmentosa with bionic eye devices. The devices stimulate the neurons with lights. At the other hand, other scientists have investigated CRISPR gene editing technique to repair the mutations that cause blindness.
This time, scientists from Italian Institute of Technology have developed a new approach. They have developed an artificial retinal implant technique to treat lost visions. This artificial retinal implant works with an artificial limb implanted into the eye. It means, the limb becomes a replacement for a damaged retina.
Scientists develop this retinal implant from a thin layer of conductive polymer that placed on a silk-based substrate. Next, they covered the implant by the semiconducting polymer. This semiconducting polymer absorbs photons when light enters and mimics as a photovoltaic material. It then stimulates retinal neurons via electricity. The electricity then fills the gap left by the eye’s natural but damaged photoreceptors.
For testing purpose, scientists placed this artificial retinal implant in the eyes of rats bred. Through this, they could make a promising rodent model of retinal degeneration.
When they treated rats from 30 days later, scientists found that the rats are now a lot sensitive to light than healthy rats.
At the intensity of around 4–5 lux, the treated rats was found largely indistinguishable from healthy animals.
During tests, scientists even manipulated rat’s brain activity via positron emission tomography (PET). They found the increment in the activity of the primary visual cortex.
That means, this artificial retinal implant directly activates residual neuronal circuitries in the degenerate retina.
Ophthalmologist Grazia Pertile said, “We hope to replicate in humans the excellent results obtained in animal models.”
“Now, we are planning to carry out the first human trials in the second half of this year and gather preliminary results during 2018. This [implant] could be a turning point in the treatment of extremely debilitating retinal diseases.”
“Still further research is required to explain exactly how the stimulation works on a biological level.”