Which ocular structure can an A-scan help diagnose cataracts?

An A-scan ultrasound is a diagnostic tool that provides valuable information about the lens of the eye, specifically its density and morphology. When assessing for cataracts, the density of the lens is particularly important because cataracts result in increased opacification of the lens, which can significantly alter its acoustic properties. By analyzing the A-scan data, sonographers can evaluate these changes in the lens, which helps in diagnosing the presence and severity of cataracts.

The A-scan is designed to deliver precise measurements of the various ocular structures and is most effectively used for the evaluation of the lens compared to other structures such as the cornea, retina, or optic nerve head. While other imaging modalities might be utilized for those specific anatomical structures, the A-scan's primary application in cataract detection is its ability to assess the lens, making it the most relevant choice in this context.