Nobel-winning therapy shows early promise in blind patients

Patients with blindness caused by retinitis pigmentosa regained the ability to detect objects in a small trial of a treatment based on research that won the 2026 Nobel Prize in Physiology or Medicine, demonstrating the potential of a novel approach.

Optogenetic therapy uses light to control brain cells. In the study, researchers combined a gene therapy that made surviving retinal ganglion cells sensitive to light with a device that delivered light to stimulate those cells.

Each of the 10 participants received an injection into one eye carrying genetic instructions for ChrimsonR, a light-sensitive protein from GenSight Biologics (SIGHT.PA). The patients then wore goggles that captured visual information and converted it into patterns of light at wavelengths that activated ChrimsonR in the modified retinal cells. The goggles then sent the patterns back to the eye.

Seven patients became more sensitive to light, and six achieved clinically meaningful improvements, such as detecting when an object was present, determining where it was located and reaching toward it accurately.

One severe adverse event occurred immediately after injection and resolved within minutes, the researchers reported in The New England Journal of Medicine.

The researchers said larger studies were needed to prove definitively the usefulness of ChrimsonR and the goggles. But they added that the findings show that even at a very advanced stage of blindness, surviving retinal ganglion cells can be made responsive to light and can transmit visual information to the brain.

"Even in people with profound vision loss, the visual system retains a remarkable capacity to process new information," said Dr. José-Alain Sahel, the study's leader, of the University of Pittsburgh.