Long-term restoration of visual function in end-stage retinal degeneration using subretinal human melanopsin gene therapy.
De Silva SR., Barnard AR., Hughes S., Tam SKE., Martin C., Singh MS., Barnea-Cramer AO., McClements ME., During MJ., Peirson SN., Hankins MW., MacLaren RE.
Optogenetic strategies to restore vision in patients who are blind from end-stage retinal degenerations aim to render remaining retinal cells light sensitive once photoreceptors are lost. Here, we assessed long-term functional outcomes following subretinal delivery of the human melanopsin gene (OPN4) in the rd1 mouse model of retinal degeneration using an adeno-associated viral vector. Ectopic expression of OPN4 using a ubiquitous promoter resulted in cellular depolarization and ganglion cell action potential firing. Restoration of the pupil light reflex, behavioral light avoidance, and the ability to perform a task requiring basic image recognition were restored up to 13 mo following injection. These data suggest that melanopsin gene therapy via a subretinal route may be a viable and stable therapeutic option for the treatment of end-stage retinal degeneration in humans.