Preliminary Safety and Tolerability Results of Intravitreal Administration of Gs010, A Recombinant Adeno-Associated Viral Vector Serotype 2 (raav2/2) Containing Human Wildtype Mitochondrial Nadh Dehydrogenase 4 (nd4) Gene in Patients with Leber Hereditary Optic Neuropathy (lhon) Due to the G11778a Nd4 Mitochondrial Dna Mutation