Which condition would result in the vitreous appearing echogenic on ultrasound?

The vitreous appears echogenic on ultrasound primarily due to the presence of blood cells or other particulate matter, which is characteristic of vitreous hemorrhage. In this condition, blood enters the vitreous cavity, scattering ultrasound waves and creating a high echogenicity that is detectable on imaging. It can present as a variable echogenic appearance, often described as "snow globe" or "dot-and-dash" echoes, which distinguishes it from other conditions affecting the vitreous.

Retinal detachment typically involves separation of the retina from the underlying tissue but does not cause echogenicity in the vitreous itself. Cataract formation affects the lens, not the vitreous; thus, it doesn't contribute to echogenicity in the vitreous. Macular degeneration primarily affects the retinal layers and also does not cause the vitreous to appear echogenic. Therefore, vitreous hemorrhage remains the condition most directly associated with an echogenic appearance of the vitreous on ultrasound.