MT-ND4 and Leber hereditary optic neuropathy: Current AAVs in clinical testing mediate transduction of retinal ganglion cells (RGCs) in the macular “ring,” Müller glia, and sparse PRs adjacent to large blood vessels, some foveal cones, and non-neuronal cells of the ciliary body.121, 122, 123, 124 As such, it is not surprising that the only IVI-based clinical trials to demonstrate biological activity thus far have targeted RGCs in the inner retina either to provide direct benefit to these cells (ND4-Leber hereditary optic neuropathy [LHON])125,126 or utilize them as a depot for secretion of an anti-VEGF reagent (wet AMD).88