Leber hereditary optic neuropathy
Pronunciation: LAY-ber
Maternally inherited mitochondrial disorder causing acute or subacute bilateral vision loss, primarily affecting young males.
Full Definition
Leber hereditary optic neuropathy (LHON) is a maternally inherited mitochondrial disorder that causes acute or subacute bilateral central vision loss, predominantly affecting young males between ages 15-30. The condition results from point mutations in mitochondrial DNA that encode subunits of complex I in the respiratory chain, with the three primary mutations being at positions 11778, 3460, and 14484. Vision loss typically begins unilaterally and progresses to involve the second eye within weeks to months, resulting in bilateral central scotomas and severely impaired visual acuity. The optic discs initially show hyperemia and pseudoedema (disc swelling without leakage) before progressing to optic atrophy. While traditionally considered to have a poor prognosis, some patients experience spontaneous visual recovery, particularly those with the 14484 mutation. Recent therapeutic advances include idebenone treatment and gene therapy trials.
Usage
Usage note: Named condition; capitalize 'Leber'. Often abbreviated as LHON in clinical practice.
In Context
- "Genetic testing confirmed Leber hereditary optic neuropathy with the 11778 mutation." — Genetic counseling report
- "The young man's rapid bilateral vision loss raised suspicion for Leber hereditary optic neuropathy." — Emergency consultation