# Acute Bilateral Vision Loss in a Young Male: A Case of Leber’s Hereditary Optic Neuropathy

## TL;DR

A 24-year-old man experienced sudden vision loss due to a rare genetic disorder affecting the optic nerve, confirmed by genetic testing.

## Contribution

The case highlights the importance of genetic testing in diagnosing Leber’s Hereditary Optic Neuropathy in young males with acute bilateral vision loss.

## Key findings

- The patient had severe bilateral vision loss confirmed by visual acuity and RAPD testing.
- Genetic testing identified the 11778/ND4 mutation, confirming Leber’s Hereditary Optic Neuropathy.
- The case emphasizes the role of mitochondrial DNA mutations in causing optic neuropathy.

## Abstract

Leber’s Hereditary Optic Neuropathy (LHON) is a rare mitochondrial genetic disorder that primarily affects young adult males, leading to acute or subacute painless central vision loss. The condition results from point mutations in mitochondrial DNA, most commonly affecting the ND1, ND4, or ND6 genes, which impair the function of complex I in the mitochondrial respiratory chain. This leads to selective degeneration of retinal ganglion cells and the optic nerve, causing severe and often irreversible visual impairment.

We present the case of a 24-year-old male farmer who consulted for rapidly progressive bilateral visual acuity loss. Visual acuity was measured at 1/10 in the right eye and “counting fingers at near” in the left eye, with a left relative afferent pupillary defect (RAPD). An extensive etiological workup for optic neuropathy was conducted. Genetic testing of the MT-ND4 gene identified the 11778/ND4 mutation, confirming the diagnosis of LHON.