TUESDAY, Oct. 13, 2026 (HealthDay News) -- Intravitreal administration of a ChrimsonR-expressing adeno-associated viral (AAV) vector targeting retinal ganglion cells combined with use of light-stimulating goggles seems safe for patients with blindness due to advanced retinitis pigmentosa, according to a study published in the Oct. 8 issue of the New England Journal of Medicine.
José‑Alain Sahel, M.D., from the University of Pittsburgh School of Medicine, and colleagues examined the safety of ganglion cell-directed optogenetic therapy in 10 participants with blindness due to advanced retinitis pigmentosa. In the worse-seeing eye, a single intravitreal injection of an AAV vector encoding the red-shifted channelrhodopsin ChrimsonR was administered. Safety was assessed as the primary outcome.
The researchers found 34 ocular adverse events among nine of the 10 participants, including 23 and 10 mild and moderate events, respectively. There was one severe event -- transient occlusion of the central retinal artery -- which occurred immediately after intravitreal injection and resolved within minutes after iopidine instillation. In seven of 10 participants, light sensitivity increased, with increases ranging from a factor of 2.0 to 62.3; a clinically meaningful increase in light sensitivity was seen in six participants.
"Potentially, the approach could also help patients with other blinding diseases in which the eye's light-sensing cells have been lost, but other retinal cells -- especially retinal ganglion cells -- remain viable. Many of these patients currently have few or no treatment options," Sahel said in a statement.
The study was funded by GenSight Biologics.
