Optogenetic Therapy for Restoring Aspects of Visual Function.
José-Alain Sahel, Stefan Futterknecht, Isabelle Audo et al.
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In 30 seconds
This open-label clinical trial evaluated safety and visual-function outcomes after ganglion cell-directed optogenetic therapy in 10 participants with blindness from advanced retinitis pigmentosa. Participants received a single intravitreal injection of an AAV vector encoding ChrimsonR in the worse-seeing eye and used light-stimulating goggles. Light sensitivity increased in 7 participants, by factors ranging from 2.0 to 62.3; 6 met the study’s literature-based threshold for clinically meaningful improvement. Ocular adverse events occurred in 9 participants, including one severe but transient event. The authors concluded that the approach was safe within the limits of this small study and requires further evaluation.
Key findings
- Light sensitivity increased in 7 of 10 participants, with increases ranging from a factor of 2.0 to a factor of 62.3.
- Six participants had a clinically meaningful increase in light sensitivity, defined as an FST decrease of at least 0.6 log units.
- There were 34 ocular adverse events among 9 participants; one severe event, transient central retinal artery occlusion, resolved within minutes.
Why it matters
The findings suggest that optogenetic stimulation may restore measurable light sensitivity in some people with advanced retinitis pigmentosa, a condition that can cause irreversible blindness. The observed adverse events, including a severe transient event, also underscore the need to assess safety alongside potential functional benefit. These early results provide a basis for further study, not a definitive estimate of efficacy or risk.
What to keep in mind
The study was open-label and included only 10 participants; the clinically meaningful improvement threshold was based on literature evidence and was not prespecified in the protocol.