Coats’ disease – causes, symptoms & treatment

Coats’ disease

Coats’ disease is a congenital disease of the eyes caused by a genetic defect. Coats’ disease leads to complete blindness and can only be treated to a limited curative extent.

What is Coats’ disease?

Coats’ disease is a rare congenital eye disease that affects boys far more often than girls. The blood vessels of the retina are dilated and permeable, allowing blood and eye fluid to pass under the retina.

This causes edema, which – if the disease remains untreated – leads to detachment of the retina and finally to complete blindness.

Coats’ disease usually occurs on one side – a typical feature is a milky white film above the eye.

Pain usually does not occur. Sometimes glaucoma is caused by the increase in intraocular pressure. Less than ten percent of those affected have no symptoms at all. In the long term, Coats’ disease threatens complete blindness.


The causes of Coats’ disease are currently unknown. However, numerous studies in the family environment of those affected allow the conclusion that there is a hereditary predisposition to the development of Coat’s disease.

A retardation of the X chromosome is suspected. The cause of blindness, to which Coats disease usually leads, are the defective blood vessels in the eye. As a result of this defect, sacs (aneurysms) develop in the blood vessels of the retina, which cause the blood vessels to become porous and allow fluids to escape.

The fluids (blood, cholesterol crystals, lipids) are deposited under the retina and lead to a detachment of the retina in the further course. As a result, the patient’s eyesight will decline more and more and ultimately lead to blindness.

Symptoms, complaints & signs

The first symptoms of Coats’ disease usually appear in the first or second decade of life. Boys are affected much more often than girls. In addition, in over 90 percent of cases, it is a unilateral eye disease caused by aneurysms of the eye blood vessels. As a rule, secondary strabismus and leukocoria are observed as initial symptoms.

In leukocoria, the fundus of the eye does not appear red as usual in photographs taken with flash, but white. In the affected eye, patients can often only see blurred. Spatial vision is impaired. However, in young children, vision loss is often not noticed at first.

However, not every course of the disease is the same. Thus, the progression of the disease can come to a temporary or even permanent standstill.

In a few cases, even an improvement in symptoms was observed. However, in most cases, retinal detachment occurs, which then leads to blindness of the affected eye. The course of the disease is often much more fulminant in children under the age of five than in older children. In severe cases, removal of the eyeball may be necessary.

Diagnosis & course

If Coats disease is suspected – secondary strabismus can be a first, visible sign – the ophthalmologist will perform an ophthalmoscopy (examination of the fundus). For this purpose, the doctor illuminates the fundus of the eye and can thus detect altered blood vessels. The examination is painless and takes only a few minutes.

Patients suffering from Coats’ disease initially show a secondary squint, it is also particularly noticeable that eyes photographed with flash do not appear red, but milky white. During this phase of the disease, the patient’s spatial vision is limited, and he perceives images only blurred. The course is usually painless – only when the intraocular pressure increases, the patient feels pain in the eye.

The increase in intraocular pressure can lead to “glaucoma”, a common concomitant disease of Coats’ disease. In affected infants, the disease usually goes unnoticed because they do not notice the constant loss of their vision. In addition, the course is different for each patient – while in most patients the deterioration occurs continuously, some patients report a relapsed deterioration. In a few cases, a regression could even be observed. As a rule, however, Coats’ disease leads to complete detachment of the retina and thus complete blindness.


Coats’ disease causes severe eye discomfort and vision loss. In the worst case, this can also lead to complete blindness, which can usually no longer be cured. Not infrequently, visual problems or blindness lead to severe mental limitations or depression.

Those affected often suffer from inferiority complexes or reduced self-esteem. Especially for young people, dealing with vision loss is relatively difficult. Those affected can continue to squint and see only blurred. It comes to a veil vision and in some cases also to double vision.

Furthermore, a glaucoma or a cataract can develop and the eyes have different eye colors. Complete blindness usually occurs only when there is no treatment of the disease. The treatment itself can be relatively simple and does not lead to special complications.

The visual problems can thus be solved and complete blindness can be prevented. Special complications do not occur. Furthermore, the pain is also limited by the treatment. Coats’ disease does not lead to a reduction in life expectancy.

When to go to the doctor?

In case of impaired vision, a doctor is always needed. If there is an obliquity of the eyes or other peculiarities of the pupils, a doctor should be consulted. Burst blood vessels in the eyeball, redness of the eyes and clouding of the cornea should be examined and treated by a doctor. Since Coats’ disease is a genetic disease, in many cases an irregularity is detected immediately after birth. Often, the diagnosis can be made after the first examinations shortly after delivery. In a routine procedure, the newborn is intensively examined by the nurses, midwives or doctors present. The dysfunction of the eyes can therefore already be tested at this stage of life.

If parents notice any abnormalities in their children’s vision during the growth and development process, they should consult a doctor immediately. If there are more accidents in everyday life or if the toddler regularly reaches next to objects, he needs medical help. If the suspicion arises that there is a complete inability to see, it is advisable to see a doctor for a check-up as soon as possible. If the child cries continuously, this can be an indication of pain or a strong internal pressure in the eye. A doctor must be consulted so that treatment can be initiated.

Treatment & Therapy

If Coats’ disease is detected early – i.e. before the first detachments of the retina – it can be treated well. The aim is to preserve part of the eyesight. An ophthalmologist can localize changed blood vessels and in a subsequent step use a laser to obliterate them.

Good treatment successes can also be achieved in this phase of the disease with cold therapy . Both therapies prevent the escape of fluid and thus prevent detachment of the retina. If Coats’ disease is more advanced and the retina has already become detached, Coats’ disease can no longer be treated curatively. The doctor can only remove the affected part of the vitreous body of the eye and/or the retina.

In order to rule out a malignant background – such as retinoblastoma – it may be helpful to remove the eye completely. Vision cannot be restored after the detachment of the retina – only the intraocular pressure can be released by the described interventions and thus pain in the eye can be reduced or completely eliminated.

Outlook & Forecast

Coats’ disease offers a relatively good prognosis. Usually only one eye is affected by the disease, which can be surgically removed. Those affected can then lead a normal, symptom-free life. However, there is a great risk of relapse in Coats’ disease. In case of relapse, the therapeutic measures must be repeated. Drug treatment of pain is associated with side effects and interactions.

If left untreated, the disease progresses progressively and leads to complete blindness of the affected eye. An effective treatment is not yet available. The therapy focuses on removing the diseased components of the body and treating the pain with medication. Well-being is reduced during treatment. After completion of therapy, a normal life is often possible.

In the case of complete blindness, the sufferers are dependent on help for the rest of their lives. Life expectancy is not reduced if the retinal edema has been completely removed. Further preventive measures are necessary to avoid a relapse, which is usually more severe and significantly worsens the prognosis. The doctor makes the prognosis, taking into account the symptoms and the chosen therapy.


Since a hereditary background is suspected in Coats’ disease , the current state of medical research cannot prevent it. If Coats’ disease is detected early, however, the consequences of the disease – usually complete blindness – can be prevented. There are a number of prophylactic therapies to choose from that aim to preserve part of your vision.


After treating Coats’ disease with laser therapy, the patient should avoid physical exertion for a few days. Active participation in road traffic is not possible 24 hours after the treatment. In the event of any abnormalities or complaints, the doctor treating you must be informed immediately. He also decides when it is time for the first check-up and whether eye drops or eye ointment need to be prescribed after the procedure.

Coats disease can only be treated symptomatically. The symptoms can therefore flare up again at any time, even after successful therapy. In addition, Coats’ disease increases the likelihood of developing increased intraocular pressure (glaucoma) or clouding of the lens (cataracts). Therefore, regular ophthalmological checks are essential. The treating ophthalmologist determines the interval between the examinations.

In some cases, despite regular therapy and check-ups, a gradual loss of vision cannot be stopped. In the worst case, patients lose the affected eye. This represents a great psychological burden for the mostly very young patients, which is why psychological care should be considered. Support from trained specialists facilitates healthy psychological development and supports the self-confidence of those affected.

What you can do yourself

The congenital disease is based on a genetic defect. The possibilities of self-help are very limited in this disease. A cure cannot be achieved despite all self-responsible attempts. In everyday life, care must be taken to maintain and improve well-being. The should be promoted so that the patient has sufficient emotional resources available in dealing with the disease. A positive attitude, encouraging words from relatives and a stable social environment help the patient to cope with everyday life.

Although many activities cannot be carried out due to the complaints, the sense of achievement should be encouraged in children. An exchange with other sufferers or in self-help groups can help to get mutual support and tips. Open questions are clarified so that a better handling of the complaints can take place in the daily routine.

The patient should be informed in a timely and comprehensive manner about his illness and its consequences. A self-confident and honest approach to the disease is helpful for the entire environment. This reduces inappropriate statements or unwanted behavior. In a large number of cases, people from the immediate vicinity experience their own insecurity or excessive demands on the situation through ignorance, which lead to misunderstandings or hurtful events for the person concerned. This should be prevented as far as possible.

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Hello! I am Lisa Newlon, and I am a medical writer and researcher with over 10 years of experience in the healthcare industry. I have a Master’s degree in Medicine, and my deep understanding of medical terminology, practices, and procedures has made me a trusted source of information in the medical world.