Case Report: An Unusual Presentation of Leber's Hereditary Optic Neuropathy

Abstract

Significance: Leber's hereditary optic neuropathy (LHON) is often associated with onset in the young, adult male demographic. This case report serves as a reminder that it can affect both sexes with onset into middle age.

Purpose: Leber's hereditary optic neuropathy is a maternally inherited mitochondrial disorder that typically affects men during young adulthood. It presents with a rapid, yet painless loss of vision, with the fellow eye often affected within a few months. The optic neuropathy causes a dense central scotoma with visual acuities reduced to less than 20/400.

Case report: A 60-year-old White woman presented with reports of decreased vision in both eyes for the previous 2 months. She had been followed up for the previous 5 years for glaucoma suspect monitoring, with full fields and normal optical coherence tomography scans. Entering visual acuity was finger counting at 1 m in the right eye and 20/100 in the left eye. Pupil testing revealed a grade 1 relative afferent pupillary defect in the right eye. Dilated fundus examination revealed stable moderate optic nerve cupping and intact neuroretinal rim tissue. Humphrey 24-2 Swedish Interactive Thresholding Algorithm standard visual field testing showed a significant superior altitudinal defect and inferior paracentral defect in the right eye and a partial superior arcuate in the left eye. The result of the MRI with contrast of the head and orbits was normal. A history of alcoholism was elicited, and LHON testing revealed positive 11778 mutation at homoplasmy.

Conclusions: Although still uncommon, presentation of LHON in a middle-aged woman is possible and should be considered a viable differential diagnosis when individuals present with painless vision loss and central/centrocecal scotomas.