In the context of ophthalmic ultrasound, what does the term "echo" refer to?

In the context of ophthalmic ultrasound, the term "echo" refers specifically to the reflection of sound waves. When ultrasound is performed, high-frequency sound waves are emitted into the eye or orbit. These sound waves travel through the tissues and encounter different interfaces within the eye, such as boundaries between fluids and solid structures. When the sound waves hit these interfaces, some of the waves are reflected back to the ultrasound transducer. This reflected sound determines the echogenicity of the various tissues, which can help in identifying their characteristics and pathologies.

The captured echoes are processed to create images that provide valuable diagnostic information about the eye's structure, including the lens, retina, and potential abnormalities. Understanding this fundamental principle of reflection is crucial for interpreting ultrasound images effectively in a clinical setting.