Coats Disease

At a glance

A disorder characterized by idiopathic progressive, retinal telangiectasia and intraretinal and/or subretinal exudation. Possibly this disease is association with renal dysfunction and cranial malformations.

Synonyms

Congenital Retinal Telangiectasia; Leber Miliary Aneurysm Disease; Exudative Retinitis.

History

First described in 1908 by the Scottish ophthalmologist George Coats (1876-1915).

Incidence

Unknown.

Genetic inheritance

Coats disease is a sporadic and generally considered nonhereditary condition. However, some experts suggest that there might be a genetic cause for the disease. Males are affected three times more often than females. No racial or ethnic predilection has been reported.

Pathophysiology

The retinal capillary endothelium is abnormally permeable. Affected vessels show marked thickening of the basement membrane and widespread loss of endothelial cells and pericytes with subsequent disintegration of the blood-retinal barrier. The retinal protein norrin, which is encoded by the NDP gene on chromosome Xp11.3 and may play a role in retinal vasculogenesis and be deficient or abnormal. There are retinal telangiectasias and aneurysms of the capillaries, venules, and arterioles. Lipoproteinaceous exudations are found in intra- and subretinal areas.

Diagnosis

Based on the clinical findings supported by fluorescein angiography, ultrasound, CT- (to rule out retinoblastoma) and/or MRI-scanning (for advanced stages of Coats Disease and also to exclude retinoblastoma). Most often Coats Disease is diagnosed by onset of retinal telangiectasias with intra- and/or subretinal exudations with an average age at onset typically between 8 and 16 years, but adult-onset has also been described.

Clinical aspects

In more than 90% of cases, Coats disease is unilateral and most frequently occurs in otherwise healthy patients. Bilateral occurrence is so rare that some researchers recommend questioning the diagnosis in these patients. The progressive disease manifests as a deterioration in either central or peripheral vision, strabismus, and/or leukocoria. Occasionally, pain, retinal detachment, heterochromia of the iris, and nystagmus may be present. Treatment depends on the stage of the disease and presence of associated symptoms. Laser photocoagulation, cryotherapy, intravitreal steroids (triamcinolone), intravitreal bevacizumab (an anti-vascular endothelial growth factor; anti-VEGF), vitreoretinal surgery, and in cases with advanced disease and pain, enucleation might be considered. Rarely, Coats disease is associated with pathologic findings of the head and neck (eg, microcephaly, intracranial calcifications, ataxia, depressed premaxillary region), the skin (eg, absent scalp hair, syndactyly of fingers, dysplastic, grooved nails), and other ocular manifestations (eg, paresis of ocular muscles, glaucoma). Renal impairment has been reported in some patients.

Precautions before anesthesia

In patients with isolated Coats disease, no specific anesthetic precautions are required. However, if there is an association with extraocular manifestations, anesthetic care is influenced by the nature and severity of these ...