Asteroid hyalosis

Asteroid hyalosis is a degenerative condition of the eye where there is an accumulation of calcium soaps in the vitreous chamber.

Epidemiology

The prevalence increases with age from 0.2% in 43-54-year-olds to 2.9% in 75-86-year-olds. The overall prevalence is 1.2%. It is more commonly unilateral and favors men over women.

Clinical presentation

It does not usually affect vision but floating opacities may cause irritation and may be confused with more common vitreous hemorrhage. It interferes with retinal examination.

Pathogenesis

The accumulated spherical opacities called asteroid bodies are made up of lipid components and calcium salt in the form of calcium phosphate apatite bound to fatty acid carboxylate groups.

Radiographic features

Ultrasound

It appears as discrete, mobile, highly echogenic, spherical or star-shaped opacities in the vitreous chamber without any posterior acoustic shadowing. Sonographic examination during eye movements, also known as oculokinetic ultrasonography, accentuates the mobile and "sparkling" nature of these opacities, allowing differentiation from vitreous hemorrhage .

Treatment and prognosis

Asteroid hyalosis is a benign condition and usually, no treatment is necessary. Vitrectomy may be indicated when it is associated with other vitreous or retinal pathologies such as proliferative diabetic retinopathy.

Differential diagnosis

• vitreous hemorrhage 
• vitreous degeneration
• vitritis
• posterior vitreous detachment
• persistent hyperplastic primary vitreous

Siehe auch:

• Sonographie des Auges