Leber Hereditary Optic Neuropathy (Sudden Vision Loss)
What is Leber hereditary optic neuropathy (LHON)?
Leber hereditary optic neuropathy (LHON), or sudden vision loss, is an inherited form of vision loss. It starts with a painless clouding or blurring in one or both eyes, and then worsens with a loss of sharpness and loss of color vision. LHON affects the central vision needed for detailed tasks such as reading, driving and recognizing faces. If you have LHON you might become legally blind.
LHON is a mitochondrial disease, which means it is only inherited through the mother. Individuals who have lost their central vision are referred to as “affected.” Individuals who carry one of the mitochondrial mutations but don’t experience vision loss are referred to as “carriers.”
Leber hereditary optic neuropathy is also sometimes called Leber’s optic atrophy or Leber’s optic neuropathy. It’s named after Dr. Theodore Leber, who studied the disease. LHON is hereditary – it’s passed down from parent to child. The word “optic” means eye, or vision. “Neuropathy” is the medical term for a disease of a nerve.
How common is Leber hereditary optic neuropathy?
Leber hereditary optic neuropathy affects one in 50,000 people.
50% of males who have the LHON mutation and 85% of females never experience vision loss.
Is Leber hereditary optic neuropathy permanent?
Most cases of Leber hereditary optic neuropathy are permanent. Around 95% of people with LHON may lose their vision before they turn 50.
Who is at risk of Leber hereditary optic neuropathy?
Leber hereditary optic neuropathy typically starts when you’re a teenager or in your twenties. Rarely, someone will have the sudden vision loss as a child or later in adulthood.
Men are affected by LHON more often than women.
The onset of symptoms occurs between the ages of 15 and 35 years in most cases. However, ages of onset between two and 87 years have been reported.
How does Leber hereditary optic neuropathy start?
Leber hereditary optic neuropathy starts with painless clouding and blurring of vision. The vision loss may start in one of your eyes, or in both. Typically you’ll see clouding and blurring in your unaffected eye after several weeks or months.
What are the risk factors associated with Leber hereditary optic neuropathy?
If you have the mutation in the mitochondrial DNA, this does not mean you will experience vision loss. Expression of the gene varies with the mitochondrial mutation. In most mutations, females have about a 15% chance and males have about a 50% chance of being affected. Some doctors believe that toxic substances may trigger the onset of blindness. It is suggested that people with a LHON mutation avoid certain substances including smoke, alcohol and paint fumes.
Symptoms and Causes
What causes Leber hereditary optic neuropathy?
LHON is a genetic condition caused by a mutation in the mitochondrial DNA. It’s caused by mutations in the following genes:
Vision loss occurs because the cells in your optic (eye) nerve die. The optic nerve relays visual information from your eyes to your brain and once these cells die the optic nerve can no longer do its job effectively. Some studies have shown that smoking and drinking alcohol may contribute.
You may get LHON even though there are no other cases in your family.
What are the signs and symptoms of Leber hereditary optic neuropathy?
LHON typically starts with painless, visual blurring that affects the central visual field in one eye. The other eye develops similar symptoms two to three months later. In about 25% of cases, both eyes develop vision loss simultaneously. As time goes on, you may lose sharpness of vision (visual acuity) and color vision.
In most cases, vision loss is the only symptom of LHON. However, a condition described as “LHON plus” sometimes occurs. Those additional symptoms include:
- Movement disorders.
- Cardiac conduction defects (problems with the electrical signals that control your heartbeat).
- Leigh syndrome.
- Symptoms similar to multiple sclerosis (these are most likely to occur in women). Those symptoms include muscle weakness, poor coordination, numbness and more. LHON-MS (multiple sclerosis) can sometimes include eye pain and problems with the central nervous system.
How do you get Leber hereditary optic neuropathy?
Leber hereditary optic neuropathy is a mitochondrial disease, which means you inherit it through your mother.
Do certain foods worsen or improve Leber hereditary optic neuropathy?
None. No foods or drinks affect LHON.
Is Leber hereditary optic neuropathy painful?
Classic Leber hereditary optic neuropathy is not painful. LHON-MS (multiple sclerosis) may include some eye pain.
Diagnosis and Tests
How is Leber hereditary optic neuropathy diagnosed?
Your healthcare provider will test your eyes and, if they suspect that your symptoms are caused by LHON, they can order a blood test to see if you carry a mitochondrial mutation.
What questions might my healthcare provider ask to diagnose Leber hereditary optic neuropathy?
- Does anyone in your family have Leber hereditary optic neuropathy?
- Have you heard of any of your ancestors having LHON?
- When did your vision start to go blurry or foggy?
- Is your vision impaired in one eye or in both?
- Are you able to recognize faces?
- Are you able to read?
- Are you able to drive?
Management and Treatment
Is there a cure for Leber hereditary optic neuropathy?
As of now there is no cure for Leber hereditary optic neuropathy. However, some people may recover some (not all) of their sight. This is rare with the 11,778 mutation but more likely with the 3,460 and 14,484 mutations.
How is Leber hereditary optic neuropathy treated? What medications are used?
Currently, there is no approved treatment for Leber hereditary optic neuropathy. Taking vitamin C, vitamin E and vitamin B12 is sometimes recommended.
Regarding medications, a clinical trial of Idebenone, a synthetic form of Coenzyme Q10, has shown effectiveness in about half of the cases. Another treatment that shows promise is the Food and Drug Administration (FDA) approved EPI-743 drug. This drug is similar to Idebenone but contains a slight difference that may allow for increased vision recovery.
Continued research is needed in order to find a safe and effective treatment. Clinical trials are in progress. Experts are exploring hormone therapy, mitochondrial replacement and gene therapy.
There are support services available if you have LHON:
- Visual aids.
- Occupational rehabilitation.
- Social services.
What are the surgical treatments for Leber hereditary optic neuropathy?
At this time there are no surgical treatments available.
Are there complications/side effects of treatment?
No complications at this time.
What healthcare provider will manage my Leber hereditary optic neuropathy?
If you have symptoms of Leber hereditary optic neuropathy, you should be monitored and helped by an ophthalmologist (eye care specialist) or neuro-ophthalmologist. If you have LHON plus, you’ll be monitored by a multidisciplinary team of healthcare providers who specialize in your eyes, heart and brain.
Can Leber hereditary optic neuropathy be prevented?
Unfortunately, you can’t avoid faulty genes inherited from your mother.
If you plan to be a mother, you can do some prenatal testing to determine the genetic risk of Leber hereditary optic neuropathy. Your healthcare provider may offer genetic counseling, which is where you’ll discuss the potential risks to your children. With that information you can make your family planning decisions.
What medicines can I take to reduce my risk of Leber hereditary optic neuropathy?
No medications are known to prevent or reduce your risk of Leber hereditary optic neuropathy.
Outlook / Prognosis
What is the prognosis (outlook) for people with Leber hereditary optic neuropathy?
Individuals with LHON may have permanent vision loss. Once central vision loss occurs, you’ll typically not see any improvement in vision and can be considered legally blind. In some cases, individuals who suffered vision loss have an improvement of central vision within twelve months. However, this is rare and may depend on what type of LHON mutation the individual has.
Can Leber hereditary optic neuropathy go away on its own?
In rare cases the vision has improved, but LHON never goes away.
How can my friends and family help?
Tell your friends and family about your symptoms and make them aware of your limitations and prognosis.
When should I see my healthcare provider?
If you have problems with your vision, whether there’s a history of Leber hereditary optic neuropathy in your family or not, see your healthcare provider immediately. Do not wait to see if it gets worse.
A note from Cleveland Clinic
Leber hereditary optic neuropathy can be a devastating diagnosis. Legal blindness will change your life. Experts are working to find a treatment but, in the meantime, listen to your healthcare provider’s instructions and rely on your family, friends and service providers.
Cleveland Clinic is a non-profit academic medical center. Advertising on our site helps support our mission. We do not endorse non-Cleveland Clinic products or services. Policy