Leber hereditary optic neuropathy

What is Leber hereditary optic neuropathy?

Leber hereditary optic neuropathy (LHON) is an inherited condition that affects the optic nerve (the specialised cable that sends visual information from the eye to the brain). It causes sight loss in the centre of the field of vision. 

What causes Leber hereditary optic neuropathy?

Leber hereditary optic neuropathy is a genetic disorder - so far, four genes have been linked to the condition. A problem with any one of these genes can cause a problem with the ‘power-houses’ that generate energy inside cells (mitochondria) and the optic nerve wastes away. 

The affected gene is passed on from mothers to their sons and daughters (although daughters do not usualy develop symptoms).

Some people may develop Leber hereditary optic neuropathy even when there is no family history of the condition. This is because people can carry a faulty gene without ever getting symptoms themselves.

What are the signs and symptoms of Leber hereditary optic neuropathy?

The first signs may be slightly blurred vision or trouble seeing colours in one eye, followed by the other eye a few weeks or months later. Severe sight loss in both eyes can develop quickly, in just three or four months, but may take a couple of years.

Symptoms usually appear in your teens up to your early 30s, but can begin later in life or in young childhood.

The condition usually affects men - women are much less likely to be affected, even if they have a genetic fault linked to the condition. 

Is Leber hereditary optic neuropathy serious?

Yes, LHON often leads to significant visual impairment, and can have a major impact on daily life and activities.

Get support for coping with sight loss

How is Leber hereditary optic neuropathy diagnosed?

Diagnosis typically involves a clinical examination by an ophthalmologist who will look for signs of optic nerve damage. Genetic testing can confirm the presence of mutations in the genes associated with Leber hereditary optic neuropathy. Other tests may include specialised scans to look at the optic nerve, and assessment of visual function.

What are the treatments for Leber hereditary optic neuropathy?

There is currently no treatment for Leber hereditary optic neuropathy.

What can help Leber hereditary optic neuropathy?

Although there is no treatment, smoking and alcohol may make symptoms worse, so avoiding these is important. Supportive measures like visual aids can help you to cope with vision loss.

What research is there into Leber hereditary optic neuropathy?

We've been funding research into Leber hereditary optic neuropathy, in order to find a treatment that can prevent sight loss. This could be by gene replacement therapy, light therapy, or drug treatments. We also need to understand more about the causes. At the moment, we don’t know who in a family will get symptoms and who won’t, or whether there are any things that make symptoms more likely to develop. We also don’t know why women are affected less often than men.

One of the projects we're funding is at Northumbria University, where a PhD student is working to understand why some people with the gene mutation develop symptoms when others don't. The aim is to learn how retinal ganglion cell degeneration can be prevented.

See our research projects