Scientists have for the first time succeeded in partially restoring the sight of a blind patient by altering his cells, according to the results of a groundbreaking study published on Monday. The technique known as optogenetics, which has been developed in the field of neuroscience over the past 20 years, involves genetically modifying cells so that they produce more light-sensitive proteins. In some cases of blindness, known as hereditary photoreceptor diseases, the light-sensing cells in the retina that use proteins to deliver visual information to the brain via the optic nerve gradually degenerate. Scientists in Europe and the United States recruited a man who lost his sight due to an inherited photoreceptor disease 40 years ago and began treating him with optogenetic techniques. It involved injections into his eye and several months of stimulation with light-emitting glasses, which transformed images of the visual world into pulses of light projected into the retina in real time. In a first clinic, they were able to restore a partial view to the 58-year-old patient, leaving him able to recognize, count, locate and touch various objects placed on a table in front of him.
Jose-Alain Sahel, lead author of the study from the French University of the Sorbonne and the National Center for Scientific Research, said the trial provided proof of concept confirmation that it was possible to use optogenetics to restore sight in humans.
“It is important to note that blind patients with different types of neurodegenerative photoreceptor disease and a functioning optic nerve will be potentially eligible for treatment,” he said.
“However, it will be time before this therapy can be offered to patients,” added Sahel, who is also a professor in the ophthalmology department at the University of Pittsburgh School of Medicine.
During the tests, the patient was able to locate and touch a notebook on a table in front of him 92% of the time while wearing the glasses. Without them, he couldn’t perform any visual task.
Botond Roska, of the Basel Institute of Molecular and Clinical Ophthalmology, said the patient was initially frustrated because he could not perceive objects even after months of training with the glasses.
“And then spontaneously you start to get very excited, reporting that he could see and be very excited about this achievement,” said Roska, co-author of the study published in the Nature Research Journals.