What is the primary use of A-scan biometry?

The primary use of A-scan biometry is for intraocular lens (IOL) calculations. This ultrasound technique measures the axial length of the eye, which is essential for determining the appropriate power of the IOL to be implanted during cataract surgery or refractive lens exchange. Accurate IOL power calculation is critical to ensure optimal vision correction following surgery, making A-scan biometry a vital tool in the preoperative assessment of cataract patients.

Other options, while relevant to ophthalmic practice, do not align with the primary function of A-scan biometry. Assessing ocular pressure is typically performed using tonometry, measuring visual acuity involves subjective testing methods, and determining refractive error is done through refraction techniques. Each of these areas utilizes different methods and instruments than those employed in A-scan biometry.