An A-scan (Amplitude Scan) is a diagnostic tool used in ophthalmology to measure the length of the eye and assess intraocular structures. It employs high-frequency sound waves that reflect off various eye structures, such as the cornea, lens, and retina1. The reflected waves are then converted into electrical signals, which are displayed on a screen as a series of peaks and valleys, representing the distances to these structures.
In the context of laser cataract surgery, the A-scan is crucial for determining the appropriate power of the intraocular lens (IOL) that will be implanted to replace the natural lens. By accurately measuring the axial length of the eye, the A-scan helps ensure that the chosen IOL will provide optimal vision correction post-surgery