Which ocular tissue produces A-scan spikes?

The lens is responsible for producing A-scan spikes in ocular ultrasound. This is due to its unique composition and the way it interacts with sound waves. In an A-scan ultrasound, sound waves are transmitted into the eye, and when they encounter different tissues, they are reflected back. Each ocular tissue has distinct acoustic properties that result in reflections at varying intensities, creating spikes on the A-scan graph.

The lens has a high acoustic density compared to surrounding tissues, which enhances the strength of the echo it produces. This results in prominent spikes on the A-scan, allowing for precise measurements of the lens's position and characteristics, which are crucial for various diagnostic and surgical applications.

In contrast, other structures such as the cornea, retina, and iris do not produce similar spikes due to their different acoustic properties. The cornea, while also reflecting sound waves, does not have the same level of reflection strength as the lens. The retina has specialized properties for light detection rather than high echo production. The iris, being a thin structure, does not contribute significantly to the A-scan readings. Therefore, the lens is the ocular tissue that generates A-scan spikes, making it the correct answer.