Restoring Vision

"The retina is a biological computer at the back of your eye. It's like a hamburger, the top bread is a photosensitive layer and the bottom bread forms the optic nerve and talks to the rest of our brain. In between, representing the salad, tomato and meat, are the computational layers that compute the visual field."

"In retinitis pigmentosa, the photosensitive layer is damaged but the rest is intact, like a hamburger without the top bread."

"In optogenetic therapy, we create an artificial photosensitive layer targeting ganglion cells, which are the lower bread. The brain has to learn a new language because the signals from the ganglion cells are not the usual ones."

Botond Roska, professor, founding director, Institute for Molecular and Clinical Ophthalmology, University of Basel, Switzerland

"Before the treatment the patient couldn't see anything but spontaneously he was able to see stripes on the street and then was able to detect objects on the table and to grasp the objects, and count the objects."

Jose-Alain Sahel, professor of Ophthalmology, Medical School of the Sorbonne Université and Founder and Director, The Vision Institute, Paris, ...Sorbonne University, Paris

A 58-year-old man who lost his sight nearly four decades ago successfully locates various objects placed on a white table following an experimental procedure that involved genetically modifying one of the man's eyes.  Jose-Alain Sahel/Botond Roska

Lacking sight for a period of forty years it could only seem like a miracle to someone who has taken part in an experiment to restore his eyesight through a new medium that will task his brain to adjust to signals received in a different way, enabling him to 'see' again. The man had undergone the fate of those who suffer from retinitis pigmentosa, where the top layer of the retina degenerates, leaving the eye incapable of sensing light.

Scientists had theorized that the intact ganglion cells at the retina base could be repurposed as light-sensitive cells, in essence repairing the damaged top layer of the retina to enable the man to see again. Now that the man has undergone the experimental treatment where his eye cells were modified genetically to become sensitive to light, he is able once again to see.

One of his eyes was modified through inserting genes from light-sensitive algae into the ganglion cells. Those cells are triggered into action with the use of special goggles which record the world in real time, converting image into pulses of red and amber light to shine into the retina, activating cells connected to the optic nerve, thus restoring sight.

The man who had undergone the experimental treatment was able to recognize, count, locate and touch objects where to do so had eluded him for decades. The work was published in the journal Nature Medicine, attracting much attention from the medical community, leading British scientists to consider the outcome a brave new experiment in rectifying a critical organ failure.

No treatment exists for retinitis pigmentosa beyond gene replacement therapy appropriate only when the eye disease is in its early onset, and it works to prevent further damage. It is believed by the scientists involved in this ground-breaking procedure that the patient's eyesight will gradually improve as the patient is trained to make the most of its potential in brain-eye communication.

 

The researchers feel that the technique will have great take-up in the impaired-vision community in part reflecting the simplicity of the gene insertion technique and the use of non-intrusive goggles to accomplish the seemingly impossible; restoring long-lost eyesight.

The treatment regimen enabled the unnamed man to 'locate, count and touch' different objects. (Nature Medicine)