In the journal Nature Materials, a team of researchers from the Italian Institute of Technology in Genoa (IIT) announces that they have developed and tested a retinal implant that can restore lost vision in rats. Clinical trials are already planned for the end of 2017.
This new implant converts light into an electrical signal that stimulates retinal neurons and now brings hope to the millions of people who suffer from retinal degeneration (including retinitis pigmentosa) which is characterized by the degeneration of cells into cones and into rods responsible for vision. The retina, located in the background of the eye, is made up of millions of light-sensitive photoreceptors and several known factors such as age, smoking, UV exposure or even genetic factors can lead to its degeneration. . On the other hand, while in the event of retinal degeneration the photoreceptor cells die, the neurons of the retina are not affected.
Because the retinal nerves remain intact and functional, the team of researchers from the Italian Institute of Technology in Genoa (IIT) led by Fabio Benfenati imagined a few months ago a prosthesis implanted in the eye which would absorb photons when the Light enters the lens to stimulate retinal neurons like a photovoltaic panel, filling the void left by the eye’s natural but damaged photoreceptors. The implant, made from a thin layer of conductive polymer placed on a silk-based substrate and coated with a semi-conductive polymer, has just been tested in rats bred to develop retinal degeneration and the results are very conclusive.
The researchers not only succeeded in restoring vision in the rats in less than 30 days, but they also improved the guinea pigs’ pupillary reflex (the physiological constriction of the pupil when exposed to light). Tested six and ten months after surgery, the implants were still effective. Some, however, suffered from a slight visual impairment due to age.
For the time being, the researchers believe that the operating principle of the prosthesis remains » uncertain and they suggest that » more research will be needed to explain exactly how stimulation works at the biological level « . Although there is no guarantee to date that the results observed in rats will translate to humans, they remain very confident. They also plan to carry out the first clinical trials in the second half of this year and to collect the preliminary results during 2018.
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