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What is LHON?
Symptoms
How LHON impacts vision
Prevalence of LHON
Importance of early diagnosis
Role of genetics and inheritance

What is LHON?

Leber’s hereditary optic neuropathy or LHON is a rare inherited condition that results in rapid central vision loss.Footnote1,Footnote2 Named after Theodore Leber, who first defined it in 1871, LHON affects approximately 1 in 45,000 people in Europe.Footnote2,Footnote3

Symptoms

Symptoms of LHON usually begin with sudden painless blurring and clouding of central vision in one eye and then both eyes.Footnote3,Footnote4 It results from cell dysfunction in the optic nerve and affects how patients can see things.Footnote3

How LHON impacts vision

Normal vision
Normal vision example
LHON vision
LHON vision example
These images are for illustrative purposes only. A patient's vision may differ from that represented in the image on the right.

Individuals with LHON develop visual blurring affecting the central vision, however in some cases the peripheral vision is preserved.Footnote1,Footnote4,Footnote5 LHON affects the central vision needed for routine tasks such as reading, driving and recognising people.Footnote4,Footnote6 This vision loss is often severe.Footnote6

Prevalence

In men

Men are four to five times more likely to be affected by LHON than women.Footnote4,Footnote5

In women

The age of onset tends to be higher in women.Footnote6

Role of genetics and inheritance

LHON is a rare condition mostly caused by mutations in the mitochondrial DNA.7 A mother with a mitochondrial mutation passes it on to all her children.Footnote7 However, a father who has LHON cannot pass it on to any of his children.Footnote4,7

Mothers with an LHON mutation (who may or may not be affected by the condition) will pass it on to their children.Footnote4

Importance of early
diagnosis

If you know anyone experiencing problems with their eyesight, such as sudden blurring or clouding in the centre of their vision, ask them to visit their GP or approach an ophthalmologist. Patients with LHON are often young adults with preserved peripheral vision, who make excellent candidates for low vision rehabilitation.Footnote1

Since LHON is a rare disease, it’s often misdiagnosed, resulting in diagnosis delays.Footnote3

  • DNA: This is the hereditary material located inside the cells in our body and contains the information needed for that cell, and our body, to develop and function. This information is passed from parents to their children through DNA.Footnote8

    Mitochondria: These are small structures (organelles) that exist inside our cells and generate the energy needed for that cell to function.Footnote8,9

    Mitochondrial DNA (mtDNA): DNA that is found in the mitochondria.Footnote8

    Mutations: The genes in our body act as instructions to make molecules called proteins. Changes in a gene are called mutations. These prevent one or more of the proteins to do their jobs causing disease.Footnote8

    Optic nerve: The nerve that carries visual information from the retina to the brain.Footnote10

    Retinal ganglion cells: These are cells that connect the inner retina of the eye to the brain. Together, these cells form the optic nerve.Footnote10,11

    1. Theodorou-Kanakari A, et al. Adv Ther. 2018;35:1510–18.

    2. Carelli V, et al. J Neuro-Ophthalmol. 2017;37:371–81.

    3. Carelli V, et al. Eur Ophthalmic Rev. 2019;13(Suppl 2).

    4. Yu-Wai-Man P and Chinnery PF. Leber Hereditary Optic Neuropathy. GeneReviews® [Internet]. 2021. Available at: https://www.ncbi.nlm.nih.gov/books/NBK1174/. Accessed: March 2023.

    5. Yu-Wai-Man P, et al. Eye (Lond). 2022:36(4):818–26.

    6. Karaarslan C. Adv Ther. 2019:36;3299–307.

    7. Fraser JA, et al. Surv Ophthalmol. 2010;55:299–334.

    8. Genetic Alliance. The New York-Mid-Atlantic Consortium for Genetic and Newborn Screening Services. Understanding Genetics: A New York, Mid-Atlantic Guide for Patients and Health Professionals. Washington (DC): Genetic Alliance; 2009. Available at: https://www.ncbi.nlm.nih.gov/books/NBK115558/. Accessed: March 2023. 

    9. Meyersen C, et al. Clin Ophthal. 2015;9:1165–76.

    10. Carelli V, et al. Biochim Biophys Acta. 2009;1787(5):518–28.

    11. Wienbar S and Schwartz GW. Prog Retin Eye Res. 2018:67;102–17.

Disclaimer: The information on this website is intended only to provide knowledge of Leber’s hereditary optic neuropathy (LHON). This information should not be used in place of advice from a healthcare professional. Please contact your doctor for advice. This website has been produced by Chiesi Pharmaceuticals. The website has been developed in accordance with industry and legal standards to provide information for the general public about LHON. Chiesi Pharmaceuticals makes every reasonable effort to include accurate and current information. However, the information provided in this website is not exhaustive.