Abstract
INTRODUCTION: Leber hereditary optic neuropathy (LHON) is a mitochondrial disorder typically affecting young males, with rare reports of late-onset disease. Among the three primary LHON mutations, m.14484T>C is generally associated with a relatively favorable visual prognosis. However, the disease in elderly patients carrying this mutation remains poorly characterized. This case represents the oldest reported patient to date with LHON due to the m.14484T>C mutation. CASE PRESENTATION: An 89-year-old man presented with a 4-month history of painless, bilateral vision loss. The patient had a 30-pack-year smoking history and daily alcohol intake but no family history of vision loss. His best-corrected visual acuity was counting fingers at 1 foot in both eyes, with color vision loss and bilateral elevated hyperemic optic disks. OCT demonstrated relatively preserved GCIPL thickness and pRNFL elevation, and visual fields showed diffuse loss. MRI of the brain and orbits was unremarkable. Laboratory evaluation, including serum B12, was normal. Genetic testing revealed the m.14484T>C mutation in mitochondrial DNA, confirming the diagnosis of LHON. At 3-month follow-up, fundus exam showed mild disk pallor bilaterally, reduced pRNFL elevation, diffuse GCIPL thinning, and stable vision and visual field. CONCLUSION: This case represents the oldest reported patient to date with LHON due to the m.14484T>C mutation. Despite the mutation's typical association with better visual outcomes, the patient experienced progressive vision loss with no recovery. This case underscores the importance of considering LHON in elderly patients with bilateral optic neuropathy and highlights the potential impact of age and environmental exposures on disease expression and prognosis.