nerve fiber layer edema

Leber Optic Atrophy

Clinical Characteristics
Ocular Features: 

The hereditary optic atrophy of Leber usually begins during early midlife (approximately 30 years of age) and affects 4 times as many males as females.  The first symptom is usually a sudden onset of unilateral painless blurry vision, followed within two months by the same symptoms in the other eye.  In a minority of patients, vision deteriorates more slowly over several years.  Vision loss can be severe, often in the count fingers range, sometimes to no light perception.  However, not all patients have such extreme vision loss.  It is not uncommon, moreover, for some recovery of vision to occur, even months to years later. Visual field testing reveals a central or cecocentral scotoma and color vision defects.  In the acute phase the disc can be swollen and hyperemic.  The peripapillary nerve fiber layer becomes edematous while vessels on the nerve head and nearby retina appear tortuous and increased in number.  Shortly thereafter the optic disc becomes pale and visual evoked potentials confirm dysfunction of the optic nerve.

A small number of patients have an onset in childhood.

Systemic Features: 

A large number of associated neurologic abnormalities have been reported including ataxia, hyperreflexia, nonspecific myopathy, tremors, movement disorders, dystonia, and a peripheral neuropathy.  Cardiac conduction defects are present in some patients.  Some females have a multiple sclerosis-like neurologic illness.


This disorder results from mutations in mitochondrial genes.  Mitochondrial DNA has 16,500 basepairs and codes for 37 genes, many of which are involved in oxidative phosphorylation.  For example, mutations in those that encode subunits of NADH dehydrogenase, MT-ND1, MT-ND2, MT-ND4, MT-ND5, and MT-ND6, are known to be responsible for LHON but at least 18 allelic variants are suspected to be causative. 

Changes in basepairs located at base pairs 3460, 11778, and 14484 account for more than 90% of cases.  In general, there is little clinical difference in the disease resulting from these mutations.  The vision loss seems to be least among patients with mutations at bp 14484 and over 50% of patients recover some vision up to a year later.  Those with mutations m.3460G>A and m.14484T>C are more likely to have some vision recovery.  Mutations at bp 11778 tends to cause the most severe loss, especially in females.

The disorder is always inherited from the maternal side (males do not contribute mitochondria via their sperm).  Many cases seem to arise de novo but in a majority of families there is a history of a similar disease among maternal relatives.

Treatment Options: 

No effective therapy is available at this time.

Article Title: 

Hereditary optic neuropathies share a common mitochondrial coupling defect

Chevrollier A, Guillet V, Loiseau D, Gueguen N, de Crescenzo MA, Verny C, Ferre M, Dollfus H, Odent S, Milea D, Goizet C, Amati-Bonneau P, Procaccio V, Bonneau D, Reynier P. Hereditary optic neuropathies share a common mitochondrial coupling defect. Ann Neurol. 2008 Jun;63(6):794-8.

PubMed ID: 
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