Scientists are testing out ways to restore vision for genetic-caused blindness

Scientists are making dramatic strides toward a goal that once seemed almost unimaginable: Restoring limited vision to people affected by a previously irreversible form of blindness caused by an inherited eye disease called retinitis pigmentosa.

The patients all had advanced cases of retinitis pigmentosa, which affects more than two million people world-wide. All underwent optogenetic therapy, in which an injection is used to deliver a gene into the eye to boost the light sensitivity of certain cells in the retina, a layer of tissue at the back of the eye. The companies are developing high-tech goggles that process and amplify light in a way that boosts the cells’ ability to send electrical signals to the brain. An experimental technique has been shown to restore partial vision in people blinded by a hereditary eye disease known as retinitis pigmentosa. In normal vision, light hits the retina at the back of the eye. Photoreceptor cells there convert the light into electrical signals that travel through the retina to the ganglion cells. The ganglion cells then send the signals via the optic nerve to the brain. The brain turns those signals into images. Retinitis pigmentosa causes the photoreceptor cells to break down, resulting in vision loss. Recent experiments with optogenetic therapies are starting to show some restoration of vision. The therapies deliver a gene to the ganglion cells that makes them sensitive to light. Patients then wear special goggles, which process the light... ...and amplify it to help the ganglion cells send electrical signals to the brain. Dr. Anand Swaroop, a senior investigator at the National Eye Institute in Bethesda, Md., called optogenetic therapy an exciting option for some blind people but not a cure. Once sight is lost completely, he said, "Restoring vision that allows high resolution, high sensitivity, and high detection is not simple."