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

Coats disease


Other Names:
Retinal telangiectasis; Leber miliary aneurysm
Categories:
Coats disease is an eye disorder characterized by abnormal development of the blood vessels in the retina (retinal telangiectasia). Most people begin showing symptoms in childhood. Early signs and symptoms vary but may include vision loss, "crossed eyes" (strabismus), and a white mass in the pupil behind the lens of the eye (leukocoria). Over time, Coats disease may also lead to retinal detachment, glaucoma, and clouding of the lens of the eye (cataracts). In most cases, only one eye is affected. Coats disease is not inherited and the underlying cause is not known. It has been theorized that some cases may be due to somatic mutations (acquired, not inherited) in the NDP gene. Treatment depends on the symptoms present and may include cryotherapy and laser photocoagulation (alone or in combination), steroids for inflammation, and/or surgery for retinal detachment.[1][2]
Last updated: 8/17/2017
The signs and symptoms of Coats disease typically begin at an early age (between ages 6 and 8).[3] The disorder may occur at any age, but the majority of people with Coats disease are diagnosed in the first two decades of life. Some people may have few or no symptoms, while others are very severely affected.[1] The condition is almost always progressive (symptoms get worse over time), although alternating periods of sudden worsening with periods of no apparent progression are common.[3]

Early signs and symptoms may include loss of vision, misalignment of the eyes (strabismus), and/or the development of a white mass in the pupil behind the lens of the eye (leukocoria).[1] As the disease progresses, affected people may develop glaucoma, cataracts, reddish discoloration in the iris (rubeosis iridis or neovascular glaucoma), shrinking of the affected eyeball (phthisis bulbi), and/or swelling and irritation of the middle layer of the eye (uveitis). Over time, Coats disease may cause detachment of the retina and substantial loss of vision.[1][3]

When Coats disease occurs with additional abnormalities that affect the brain, bones, gastrointestinal system, and other parts of the body, it is called Coats plus syndrome.[4]
Last updated: 8/17/2017

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

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Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Abnormal retinal vascular morphology
Abnormality of retina blood vessels
0008046
Strabismus
Cross-eyed
Squint
Squint eyes
[ more ] 		0000486
30%-79% of people have these symptoms
Abnormal macular morphology 0001103
Glaucoma 0000501
Retinal detachment
Detached retina
0000541
5%-29% of people have these symptoms
Abnormal anterior chamber morphology 0000593
Aplasia/Hypoplasia of the iris
Absent/small iris
Absent/underdeveloped iris
[ more ] 		0008053
Cataract
Clouding of the lens of the eye
Cloudy lens
[ more ] 		0000518
Percent of people who have these symptoms is not available through HPO
Exudative retinal detachment 0012231
Leukocoria 0000555
Retinal telangiectasia 0007763
Somatic mutation 0001428
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Last updated: 7/1/2020
The cause of Coats disease is not currently known. It has been theorized that somatic mutations (acquired, not inherited) in the NDP gene may lead to isolated cases of Coats disease. However, this has not been proven.[1]

Coats disease has been reported as one feature of several genetic syndromes.[3] In these cases, the underlying cause of each syndrome may be responsible for Coats disease. When Coats disease occurs with additional abnormalities that affect the brain, bones, gastrointestinal system, and other parts of the body, it is called Coats plus syndrome and is caused by mutations in the CTC1 gene.[4]
Last updated: 8/17/2017
Isolated Coats disease is not an inherited condition.[1] Rarely, Coats disease can be a feature of an underlying, inherited genetic syndrome. For example, it is a key feature of a condition called Coats plus syndrome, which is characterized by Coats disease plus abnormalities of the brain, bones, gastrointestinal system, and other parts of the body. Coats plus syndrome is inherited in an autosomal recessive manner.[3][4]
Last updated: 8/17/2017
A diagnosis of Coats disease is often suspected based on the presence of signs and symptoms, and findings on a thorough eye examination. Specialized tests to confirm the diagnosis and rule out other conditions may include retinal fluorescein angiography, diagnostic echography, and in some cases, a CT scan of the orbits, and/or MRI.[1][2]
Last updated: 8/17/2017
Treatment for Coats disease depends on the severity in each person.[1] The following treatments (used alone or in combination) may be tried:

More advanced disease with extensive retinal detachment may also require surgical interventions such as vitrectomy, scleral buckling to correct a detached retina, and external drainage of fluids.[5]

Last updated: 8/17/2017
The prognosis varies in each case. Factors that effect the prognosis include the stage of disease at the time of diagnosis, the age at diagnosis, the rate of disease progression, and the effectiveness of treatment.

In some older children and young adults, spontaneous regression (improvement of symptoms) has been reported. Younger children typically have more aggressive disease and often have a total retinal detachment by the time they are diagnosed; these children usually have a poor visual outcome.[6] Some people present with advanced disease which does not benefit from treatment, while others show disease progression despite treatment.[5] While most people respond well to treatment, approximately 25% will become worse and require removal of the eye.[5][6] An ophthalmologist with knowledge about Coats disease may be able to make a general prediction about the chances of retaining the eye and preserving vision. 

The extent of visual impairment varies considerably from person to person. Favorable visual outcomes are more likely to be achieved with early detection and treatment, with combined therapies as needed. Even when treatment is not able to restore sight, it is beneficial in saving the eye.[5]
Last updated: 8/17/2017

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

Related diseases are conditions that have similar signs and symptoms. A health care provider may consider these conditions in the table below when making a diagnosis. Please note that the table may not include all the possible conditions related to this disease.

Conditions with similar signs and symptoms from Orphanet
Retinoblastoma (see this term) is the most important differential diagnosis. B-scan ultrasound and MRI with gadolinium contrast aid in distinguishing between late stage CD and solid tumors. Others include familial exudative vitreoretinopathy, Von Hippel-Lindau disease, intermediate uveitis and incontinentia pigmenti which are more often bilateral, as well as the more typically unilateral conditions such as ocular toxocariasis and persistent hyperplastic primary vitreous (see these terms).
Visit the Orphanet disease page for more information.

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

  • ClinicalTrials.gov lists trials that are related to Coats disease. Click on the link to go to ClinicalTrials.gov to read descriptions of these studies.

    Please note: Studies listed on the ClinicalTrials.gov website are listed for informational purposes only; being listed does not reflect an endorsement by GARD or the NIH. We strongly recommend that you talk with a trusted healthcare provider before choosing to participate in any clinical study.
  • Orphanet lists European clinical trials, research studies, and patient registries enrolling people with this condition. 

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

Social Networking Websites

  • RareConnect has an online community for patients and families with this condition so they can connect with others and share their experiences living with a rare disease. The project is a joint collaboration between EURORDIS (European Rare Disease Organisation) and NORD (National Organization for Rare Disorders).

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

  • The National Organization for Rare Disorders (NORD) has a report for patients and families about this condition. NORD is a patient advocacy organization for individuals with rare diseases and the organizations that serve them.

In-Depth Information

  • GeneReviews provides current, expert-authored, peer-reviewed, full-text articles describing the application of genetic testing to the diagnosis, management, and genetic counseling of patients with specific inherited conditions.
  • 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) is a catalog of human genes and genetic disorders. Each entry has 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. 
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.
  • PubMed is a searchable database of medical literature and lists journal articles that discuss Coats disease. 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

  • My 2 year old son was recently diagnosed with Coats disease stage 3a. I would love to know more about this, the various stages and what happens in them, and the possible treatments and long term prognosis. See answer


  1. Coats Disease. NORD. 2017; http://www.rarediseases.org/rare-disease-information/rare-diseases/byID/837/viewFullReport.
  2. Hubbard B, Laird P. Coats disease. Orphanet. July, 2013; http://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=EN&Expert=190.
  3. Del Longo A. Coats disease. Orphanet Encyclopedia. September 2004; http://www.orpha.net/data/patho/Pro/en/Coats-FRenPro1645.pdf.
  4. Coats Plus Syndrome. Genetics Home Reference. April 2014; http://ghr.nlm.nih.gov/condition/coats-plus-syndrome.
  5. Cebeci Z, Bayraktar S, Yilmaz YC, Tuncer S, Kir N. Evaluation of Follow-Up and Treatment Results in Coats' Disease. Turk J Ophthalmol. October, 2016; 46(5):226-231. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5200835/.
  6. Shields JA, Shields CL, Honavar SG, Demirci H, Cater J. Classification and management of Coats disease: the 2000 Proctor Lecture. American Journal of Ophthalmology. May 2001; 131(5):572-583.