MT-ND4 and Leber hereditary optic neuropathy: RESCUE was a multicenter, randomized, double-masked, sham-controlled, phase-3 clinical trial investigating the efficacy of a single intravitreal injection of rAAV2/2-ND4 (a gene therapy vector enabling allotopic expression and delivery of the wild-type ND4 protein to mitochondria within RGCs) in subjects with visual loss from LHON (20).