Abstract
Leber hereditary optic neuropathy (LHON) is a genetic condition that typically presents with unilateral, painless, sub-acute central vision loss followed by contralateral vision loss after a few weeks to months. It is a rare disease that typically affects young adults - men more than women - and is a relatively common cause of blindness. It is due to a mutation in mitochondrial DNA (mtDNA). The majority (more than 95%) of patients have one of three mtDNA point mutations: m.14484T→C, m.3460G→A, or m.11778G→A. These mutations lead to disruption of the mitochondrial respiratory chain activating pro-apoptotic pathways. For reasons unknown, this insult tends to affect the retinal ganglion cells more than any other cell in the body, leading to the disease state. Due to its low prevalence in the United States (1:50,000), this diagnosis is often overlooked, misdiagnosed, and mismanaged, which may exacerbate symptoms. It is essential then for physicians to recognize the presentation of and understand the diagnostic work-up for LHON. In this case report, we present the diagnostic challenges of a patient who presented with progressive vision loss, discuss the various differential diagnoses, review the literature on LHON, and propose an explanatory model for vision loss in patients with LHON.