OPA1 and autosomal dominant optic atrophy: OPA1 is also essential for successful mitochondrial fusion.7,10,11 Reduced OPA1, as documented in ADOA patient cells, has been shown to negatively impact these functions and to render cells more sensitive to apoptotic stimuli.12,13 RGCs, particularly those located in the central retina or fovea, appear to be highly sensitive to reduced levels of OPA1.