Asteroid hyalosis is a condition with a dramatic clinical appearance (see Fig 17-12 in BCSC Section 12, Retina and Vitreous) but little clinical significance. Histologically, asteroid bodies are rounded structures measuring 10–100 nm, typically attached to vitreous fibrils (Fig 10-11). The bodies are basophilic with hematoxylin-eosin stain. They are usually positive with stains for calcium such as alizarin red and von Kossa. Occasionally, they will be surrounded by a foreign body giant cell reaction, but the condition is not generally associated with vitreous inflammation.
Figure 10-11 Asteroid bodies (arrows) and erythrocytic debris within the vitreous.
(Courtesy of Tatyana Milman, MD.)
Studies have shown that asteroid bodies are composed of complex lipids and also have a component with structural and elemental similarity to hydroxyapatite, a calcium phosphate complex.
Excerpted from BCSC 2020-2021 series: Section 4 - Ophthalmic Pathology and Intraocular Tumors. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.