We combined peripheral nerve grafts with gene therapy to promote long-distance regeneration of retinal axons.

There was widespread, sometimes dense reinnervation of the contralateral superficial superior colliculus.

Regenerate retinal axons formed complex arbors in superficial SC and expressed presynaptic terminal markers.

Additional neurotrophic therapy to promote axon sprouting was associated with improved visual function via the grafted eye.

Despite the robust regrowth of RGC axons back into the SC, evidence suggested a lack of order in the regenerate projection.