National Center for Advancing and Translational Sciences Genetic and Rare Diseases Information Center, a program of the National Center for Advancing and Translational Sciences

Chronic progressive external ophthalmoplegia

Chronic progressive external ophthalmoplegia (CPEO) is a condition characterized mainly by a loss of the muscle functions involved in eye and eyelid movement. Signs and symptoms tend to begin in early adulthood and most commonly include weakness or paralysis of the muscles that move the eye (ophthalmoplegia) and drooping of the eyelids (ptosis).[1][2] Some affected individuals also have general weakness of the skeletal muscles (myopathy), which may be especially noticeable during exercise. Muscle weakness may also cause difficulty swallowing (dysphagia). CPEO can be caused by mutations in any of several genes, which may be located in mitochondrial DNA or nuclear DNA. It has different inheritance patterns depending on the gene involved in the affected individual.[2]

CPEO can occur as part of other underlying conditions, such as ataxia neuropathy spectrum and Kearns-Sayre syndrome. These conditions may not only involve CPEO, but various additional features that are not shared by most individuals with CPEO.[2]
Last updated: 1/19/2017
The signs and symptoms of chronic progressive external ophthalmoplegia (CPEO) typically begin in young adults between the ages of 18 and 40.[1][2] The most common symptoms in affected individuals include drooping eyelids (ptosis) and weakness or paralysis of the eye muscles (ophthalmoplegia). The condition may be unilateral (affecting one eye) or bilateral (affecting both eyes).[3] Some affected individuals also have weakness of the skeletal muscles (myopathy), specifically of the arms, legs, and/or neck. This may be especially noticeable during exercise.[1][2] Muscle weakness may also cause difficulty swallowing (dysphagia).[2]

Sometimes, CPEO may be associated with other signs and symptoms. In these cases, the condition is referred to as "progressive external ophthalmoplegia plus" (PEO+). Additional signs and symptoms can include hearing loss caused by nerve damage in the inner ear (sensorineural hearing loss), weakness and loss of sensation in the limbs due to nerve damage (neuropathy), impaired muscle coordination (ataxia), a pattern of movement abnormalities known as parkinsonism, or depression.[2]

Last updated: 1/19/2017
Chronic progressive external ophthalmoplegia (CPEO) can be inherited, or it can occur sporadically (due to a new mutation in an individual with no history of the condition in the family).

CPEO is considered a "mitochondrial disorder." This is because all the genetic mutations that can cause CPEO ultimately result in dysfunction of the mitochondria, which are structures in our cells that produce energy required for normal cell function. While most of our DNA is located in the cell's center (nuclear DNA), some of our DNA is located within the mitochondria (mitochondrial DNA).[1] CPEO can be caused by mutations in any of several genes, which may be located in mitochondrial DNA or nuclear DNA. It has different inheritance patterns depending on the gene involved in the affected individual.[2]

Unlike nuclear DNA which is inherited from both the mother and the father, mitochondrial DNA is inherited from only the mother. In CPEO, the affected mitochondria (i.e., the ones carrying the mutations) are found only in the skeletal muscle cells. These mitochondrial DNA mutations are almost always sporadic (occurring by chance for the first time in the affected individual). Nuclear gene mutations that cause CPEO may be inherited in an autosomal recessive or autosomal dominant manner, depending on the gene involved.[1] The risk for other family members to be affected depends on the genetic cause and the inheritance pattern in the family.
Last updated: 1/19/2017
Ptosis caused by chronic progressive external ophthalmoplegia (CPEO) can be corrected by surgery, or by using glasses that have a “ptosis crutch” to lift the upper eyelids.[4] Strabismus surgery can be helpful in carefully selected patients if diplopia (double vision) occurs.[5]

Some individuals with a deficiency of coenzyme Q10 have CPEO as an associated abnormality. Coenzyme Q10 is important for normal mitochondrial function. In individuals with this deficiency, supplemental coenzyme Q10 has been found to improve general neurologic function and exercise tolerance. However, coenzyme Q10 has not been shown to improve the ophthalmoplegia or ptosis in people who have isolated CPEO.[1]
Last updated: 1/19/2017

Management Guidelines

  • GeneReviews provides a current, expert-authored, peer-reviewed, full-text article on mitochondrial disorders, including CPEO. GeneReview articles describe the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
Chronic progressive external ophthalmoplegia (CPEO) can be an isolated condition, or it can occur as part of other underlying conditions, such as ataxia neuropathy spectrum and Kearns-Sayre syndrome. These conditions may involve not only CPEO, but various additional features that are not shared by most individuals with CPEO in isolation.[2] Individuals with isolated CPEO generally have a normal life expectancy. While symptoms tend to worsen over time, the specific symptoms and their severity can vary greatly from person to person. Therefore, when symptoms first appear, the course of the condition is very difficult to predict.[1][6]

For individuals with additional symptoms or another underlying condition associated with CPEO, the prognosis depends on the specific signs and symptoms present and/or the outlook associated with the underlying condition in the affected individual. For this reason, obtaining an accurate diagnosis is very important.
Last updated: 1/19/2017

If you need medical advice, you can look for doctors or other healthcare professionals who have experience with this disease. You may find these specialists through advocacy organizations, clinical trials, or articles published in medical journals. You may also want to contact a university or tertiary medical center in your area, because these centers tend to see more complex cases and have the latest technology and treatments.

If you can’t find a specialist in your local area, try contacting national or international specialists. They may be able to refer you to someone they know through conferences or research efforts. Some specialists may be willing to consult with you or your local doctors over the phone or by email if you can't travel to them for care.

You can find more tips in our guide, How to Find a Disease Specialist. We also encourage you to explore the rest of this page to find resources that can help you find specialists.

Healthcare Resources

  • You can submit a question to Ask the Mito Doc, a service of the United Mitochondrial Diseases Foundation. Information contained in Ask the Mito DocSM is for informational and educational purposes only.

Research helps us better understand diseases and can lead to advances in diagnosis and treatment. This section provides resources to help you learn about medical research and ways to get involved.

Clinical Research Resources

  • The U.S. National Institutes of Health, through the National Library of Medicine, developed ClinicalTrials.gov to provide patients, family members, and members of the public with current information on clinical research studies. There is a study titled Screening Study for the Evaluation and Diagnosis of Potential Research Participants which may be of interest to you.
  • The North American Mitochondrial Disease Consortium (NAMDC) is a team of doctors, nurses, research coordinators, and research labs throughout the U.S., working together to improve the lives of people with this condition through research.
  • The Research Portfolio Online Reporting Tool (RePORT) provides access to reports, data, and analyses of research activities at the National Institutes of Health (NIH), including information on NIH expenditures and the results of NIH-supported research. Although these projects may not conduct studies on humans, you may want to contact the investigators to learn more. To search for studies, enter the disease name in the "Text Search" box. Then click "Submit Query".

Support and advocacy groups can help you connect with other patients and families, and they can provide valuable services. Many develop patient-centered information and are the driving force behind research for better treatments and possible cures. They can direct you to research, resources, and services. Many organizations also have experts who serve as medical advisors or provide lists of doctors/clinics. Visit the group’s website or contact them to learn about the services they offer. Inclusion on this list is not an endorsement by GARD.

Organizations Supporting this Disease

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

Where to Start

  • Genetics Home Reference (GHR) contains information on Chronic progressive external ophthalmoplegia. This website is maintained by the National Library of Medicine.

In-Depth Information

  • Medscape Reference provides information on this topic. You may need to register to view the medical textbook, but registration is free.
  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Online Mendelian Inheritance in Man (OMIM) lists the subtypes and associated genes for Chronic progressive external ophthalmoplegia in a table called Phenotypic Series. Each entry in OMIM includes a summary of related medical articles. It is meant for health care professionals and researchers. OMIM is maintained by Johns Hopkins University School of Medicine.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Chronic progressive external ophthalmoplegia. Click on the link to view a sample search on this topic.

Questions sent to GARD may be posted here if the information could be helpful to others. We remove all identifying information when posting a question to protect your privacy. If you do not want your question posted, please let us know. Submit a new question

  • Is chronic progressive external ophthalmoplegia fatal? If so, what is the life expectancy? See answer

  • I would like to learn more about chronic progressive external opthalmoplegia, particularly how it can be treated. Also does the rate of progression vary from person to person? What is the typical prognosis (long term outlook) for people with this condition? Can chronic progressive external opthalmoplegia affect facial muscles as well? See answer


  1. DiMauro S, Michio H. Mitochondrial DNA Deletion Syndromes. GeneReviews. May 3, 2011; https://www.ncbi.nlm.nih.gov/books/NBK1203/.
  2. Progressive external ophthalmoplegia. Genetics Home Reference. May 2016; http://ghr.nlm.nih.gov/condition/progressive-external-ophthalmoplegia.
  3. Van Goethem, Gert et al. . Progressive External Ophthalmoplegia Characterized by Multiple Deletions of Mitochondrial DNA. NeuroMolecular Medicine . 2003;
  4. Mitochondrial Myopathies (MM) Medical Management. Muscular Dystrophy Association. https://www.mda.org/disease/mitochondrial-myopathies/medical-management. Accessed 1/19/2017.
  5. Mercandetti M, Cohen AJ. Chronic Progressive External Ophthalmoplegia. Medscape. June 20, 2016; http://emedicine.medscape.com/article/1215103-overview.
  6. Auré K, Ogier de Baulny H, Laforet P, Jardel C, Eymard B, Lombes A. Chronic progressive ophthalmoplegia with large-scale mtDNA rearrangement: can we predict progression?. Brain. April 17, 2007; 130(6):1516-1524. http://brain.oxfordjournals.org/cgi/content/full/130/6/1516?ck=nck.