An experimental treatment combining gene therapy with light-stimulating goggles has helped some patients with profound vision loss from retinitis pigmentosa detect and locate objects, according to a small clinical trial.
Retinitis pigmentosa comprises a group of inherited disorders in which genetic changes damage the retina’s photoreceptors. Variants in more than 100 genes can cause the condition, complicating efforts to develop treatments for each genetic cause. The optogenetic approach bypasses this challenge by giving surviving nerve cells a new way to respond to light.
In the trial, published in The New England Journal of Medicine, researchers enrolled 10 participants with profound vision loss in both eyes. Each received a single injection into their worse-seeing eye. A modified virus delivered instructions to produce a light-sensitive protein called ChrimsonR in retinal ganglion cells, which transmit visual signals to the brain.
Participants then used special goggles containing a camera that captures changes in brightness. A processor converts these changes into patterns of amber light projected onto the retina to activate the protein.
Seven participants showed increased light sensitivity, ranging from approximately two-fold to 62-fold. Six reached at least a four-fold increase, which the researchers considered clinically meaningful. In object detection tests, four of eight participants consistently performed better with the goggles over sessions spanning roughly one to one and a half years.
Safety findings showed 34 eye-related adverse events among nine participants, mostly mild or moderate. Seven developed eye inflammation that resolved with treatment.
The researchers noted significant limitations. Participants still cannot recognise faces or read, and greater sensor sensitivity would be valuable. The trial was not randomised and had no control arm.
Source: Sahel JA, Roska B et al. Optogenetic therapy for retinitis pigmentosa. The New England Journal of Medicine (2026).
