Pilot Study of the Efficacy of Nicotinamide (Vitamin B3) in Leber's Hereditary Optic Neuropathy

Leber Hereditary Optic Neuropathy (LHON) is a rare genetic disease that causes sudden and severe vision loss, usually in young adults. It is linked to mutations in mitochondrial DNA that impair energy production in retinal ganglion cells, leading to degeneration of the optic nerve. Currently, treatment options are very limited and often ineffective. Recent research has shown that patients with LHON have lower levels of nicotinamide (vitamin B3), a key molecule for mitochondrial energy metabolism. Nicotinamide is a precursor of NAD, an essential cofactor for cellular energy production. Experimental studies and clinical trials in related optic nerve diseases suggest that nicotinamide may protect retinal ganglion cells. Our hypothesis is that supplementation with high-dose nicotinamide could restore NAD levels, support mitochondrial activity, and help preserve or improve vision in LHON. This pilot study will evaluate the effectiveness and safety of oral nicotinamide (2 grams per day for 12 months) in patients who developed LHON within the past 18 months and carry one of the two most severe mutations (m.11778G\>A or m.3460G\>A). The main goal is to measure changes in visual acuity over time using standardized eye charts. Secondary objectives include assessing visual fields, retinal structure by optical coherence tomography (OCT), blood nicotinamide levels, and quality of life. Liver function will be monitored to ensure safety. If this study shows promising results, it could pave the way for a larger randomized trial and ultimately offer a new therapeutic option.