Which ocular structure is primarily assessed using A-scans?

A-scans, or amplitude scans, are a type of ultrasound used in ocular diagnostics. They primarily assess the eye's internal structures by measuring the distances between those structures, which is particularly useful for determining the dimensions of the lens.

In the context of ocular assessments, the lens is a critical structure that A-scans help evaluate, especially when it comes to measuring its thickness and calculating the appropriate power for intraocular lens implants in cataract surgery. The ability to measure the lens accurately informs surgeons of the appropriate lens type and power, ensuring that postoperative visual outcomes are optimized.

While the cornea, chamber angle, and iris are essential structures of the eye, they are typically assessed using different techniques. For instance, corneal measurements are frequently conducted using topical methods, such as pachymetry or corneal topography, while the chamber angle assessment involves gonioscopy. The iris is usually examined through visually inspecting the anterior chamber. These methods target the properties and conditions of those structures specifically, rather than the detailed dimensional data that A-scans provide for the lens. Thus, the primary focus of A-scans is indeed the lens.