Leber's Hereditary Optic Neuropathy.

Background: Leber's hereditary optic neuropathy (LHON) is the most common maternally inherited disease linked to mitochondrial DNA (mtDNA). The patients present with subacute asymmetric bilateral vision loss. It is a rare disease that typically affects young adults-men more than women-and is a relatively common cause of blindness. The majority (more than 95%) of patients have one of three mtDNA point mutations: m.14484T→C, m.3460G→A, or m.11778G→ A.The hallmark of hereditary optic neuropathies determined by mitochondrial dysfunction is the vulnerability and degeneration of retinal ganglion cells (RGC). Due to its low prevalence in the population (1:50,000), this diagnosis is often overlooked, misdiagnosed, and mismanaged, which may exacerbate symptoms.

Objective: The aim of the paper is to present the complexity and challenge of making the correct diagnosis in patients with progressive vision loss.

Case report: A 42-year-old patient, female, complains of a bilateral decrease in visual acuity after surgery performed under general anaesthesia. The visual acuity value at the first ophthalmological examination was 0.8 bilaterally and could not be corrected. The OCT finding was within the ''reference values'', while the visual field finding showed non-specific changes. Further examinations by a neurologist and psychiatrist do not lead to a correct diagnosis. After a long time, genetic testing reveals a genetic mutation and a diagnosis of LHON is made.

Conclusion: Although still uncommon, the presentation of LHON in middle-aged women is possible and should be considered as one of the differential diagnoses in a patient when painless vision loss occurs.