Dominant Optic Atrophy (hereafter known as DOA) is a neurodegenerative pathology of the optic nerve inducing progressive loss of central visual field and visual acuity. There is currently no proven treatment for this disease. The metabolomics work of Pascal Reynier's team revealed a specific metabolomic signature of DOA in the plasma of patients. This metabolomic signature revealed a relative deficiency in nicotinamide compared to a control population, a vitamin compound (vitamin B3) known to be neuroprotective for the optic nerve and mitochondria. Note that the investigator have also identified this nicotinamide deficiency in primary open-angle glaucoma and Leber's hereditary optic neuropathy, the other most common cause of hereditary optic neuropathy, these three optic nerve conditions sharing a common pathophysiological mechanism of mitochondrial deficit. In addition, an American team demonstrated the high neuroprotective power on the optic nerve of nicotinamide in a mouse model of glaucoma. These arguments converge towards the potential therapeutic interest of this vitamin in degenerative pathologies of the optic nerve. This is encouraged by the fact that two randomized clinical trials have confirmed a benefit of nicotinamide in glaucoma. The objective of this pilot study is to test the tolerance and efficacy of nicotinamide in DOA and DOA+ patients.