Coats disease

What is Coats disease?

Coats disease refers to a rare eye condition that typically presents in childhood as well as adolescence and is associated with a congenital enlargement of the vessels of the retina. The condition often appears on one eye and is mainly seen in male patients, often manifesting for the first time between the ages of six and eight years.

There is an endothelial defect in the retinal vasculature that results in outpouching and vessel dilation, as well as compromised capillaries. In consequence, fluid may escape from the capillary bed, which may collect under the retina and cause fat-rich deposits. Such deposits and fluid buildup can result in detachment of the retina. If left untreated, this leads to blindness.

Causes and symptoms

Because this condition frequently runs in families, it is likely that there is genetic involvement. Up to now, some genetic defects could be described in correlation with Coats disease, with an impact on the development and growth of retinal blood vessels. Nevertheless, the exact cause of the disease remains subject of current research.

The disease may initially be totally asymptomatic. Later on, patients may experience a limitation or change in their vision. This so-called visual reduction is noticed by the patients, for example, as blurred vision. Kids who do not have symptoms are sometimes striking due to a white glow of the pupil in photos, that is caused by an altered pupillary reflex.

However, this pupillary effect could also be indicative of retinoblastoma and therefore cancer must always be ruled out as an important differential diagnosis. Some patients, on the other hand, display a sudden onset of strabismus as an early symptom. This strabismus is provoked by an axial misalignment of the eye affected. More typical symptoms may include shrinkage of the eyeball or varying coloration of the eyes.

In later stages, the inflammatory reaction within the retina along with the fat and fluid accumulations may result in detachment of the retina. The symptoms are often a painful pressure increase in the eye, called glaucoma, as well as loss of visual field and the potential perception of light flashes.

How is Coats disease diagnosed?

The first step in diagnosing Coats disease is to consult an eye doctor for a number of examinations. Among those is an ophthalmological inspection of the fundus of the eye, which reveals dilated vessels and also deposits as well as bleedings or a detachment of the retina in case it has already occurred. Furthermore, the altered blood vessel structures can be assessed more accurately by means of fluorescence angiography.

This involves giving the patient a colored contrast agent, allowing it to be visualized within the vessels. Also a sonographic examination of the eyeball can provide more insight. In some cases, young children may require anesthesia for the tests.  MRI or CT examinations may also be considered, particularly in order to rule out retinoblastoma as a differential diagnosis. Nevertheless, a definite distinction between Coats disease and retinoblastoma may not always be established.

Periodic photographic documentation of retinal lesions can be used to monitor how the disease is progressing.

What are the treatment options?

During the early stages of the disease, the blood vessels can be obliterated using laser or cold therapy so that no fluid leakage occurs. Patients with advanced disease, however, are not treatable in this way. If the retina is partially or completely detached, part of the vitreous body has to be removed by vitrectomy. Complete removal of the eye, referred to as enucleation, might also be considered if the patient's vision has already been lost and the affected eye has gone blind. On top of that, enucleation of the eye may be necessary in some cases if cancer of the eye cannot be ruled out for sure. 

Prognosis and chances of cure

If Coats disease is not treated, it will most likely lead to blindness, as the disease results in retinal detachment. Early intervention can stop many patients from losing their vision, however. Cure of Coats disease is usually not possible, but there are cases where the disease spontaneously resolves and stops progressing. Hence, a wide variety of disease trajectories have been observed.

Patients that receive a good prognosis are those whose disease is diagnosed and treated at an early stage to prevent detachment of the retina and to preserve vision. Regular check-ups with an ophthalmologist are very important.

Which doctors and clinics specialize in Coats disease?

If you're in need of a doctor, you expect the best medical care possible. So of course patients are curious to find out what clinic to go to. As there is no objective way to answer this question and a legitimate doctor would never claim to be the best, patients must rely on a doctor's experience.

Coats disease is treated and diagnosed by registered ophthalmologists and eye clinics.

Let us help you find an expert for your condition. All listed doctors and clinics have been reviewed by us for their outstanding specialization in Coats disease and are looking forward to your inquiry or wish for treatment.