Coats’ disease

Also known as: Coats’ Retinitis; Exudative Retinitis; Exudative Retinopathy; Morbus Coats’


Coats’ disease is a rare condition affecting the retina (a light-sensitive layer of tissue) at the back of the eye. It usually starts in childhood and affects one eye. It is characterised by dilation (widening) and malformation of retinal capillaries (tiny blood vessels). This results in an accumulation of yellowish fluid (exudate) leading to impaired macular (central part of the retina) function. Symptoms include strabismus (an eye turn/squint), leukocoria (white pupil), and reduced central or peripheral (side) vision. Glaucoma may be present and cause pain and loss of appetite and require specific treatments. Currently there is no known cause, although a change (mutation) in the Norrin gene has been suggested as a cause. Coats’ disease does not seem to be inherited and no other family members are affected. The diagnosis may be confirmed by examination of the inside of the eye using by an ophthalmologist (eye specialist) who will use techniques to look at the eye and the capillaries. If caught early, treatment may stop progression and loss of sight. This can involve surgery using laser light (photocoagulation) or extreme cold (cryotherapy) to close the leaking blood vessels and possibly treatment with a new drug called Avastin.

This overview is intended to be a basic description of the condition. It is not intended to replace specialist medical advice. We advise that you discuss your child’s case with a qualified medical professional who will be able to give you more detailed information.


Medical text approved February 2013 by Isabelle Russell-Eggitt, Contact a Family Medical Advisory Panel.

Inheritance patterns and prenatal diagnosis

Inheritance patterns
Usually sporadic (with no other affected family members).

Prenatal diagnosis

Is there support?

There is no support group for Coats’ disease in the UK. Cross referrals to other entries in The Contact a Family Directory are intended to provide relevant support for those particular features of the disorder. Organisations identified in those entries do not provide support specifically for Coats’ disease.

Families can use Contact’s freephone helpline for advice, information and, where possible, links to other families. You can also connect with other families in our closed Facebook group

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