Keratometry

Keratometry (K) is the measurement of the corneal curvature; corneal curvature determines the power of the cornea. Differences in power across the cornea (opposite meridians) results in astigmatism; therefore, keratometry measures astigmatism. It can be acquired with a variety of instruments either manually or via automated methods. Measurements can be very sophisticated, such as with topographers, that measure a cornea across a broad number of points, or it can be measured in a more finite area of the cornea.

Keratometry plays a very important role in
IOL Power calculation in Cataract surgery
Lasik work up
Keratoconus diagnosis
Contact lens fitting

A Scan

A-scan ultrasound biometry, commonly referred to as an A-scan (short for Amplitude scan), is routine type of diagnostic test used in optometry or ophthalmology. The A-scan provides data on the length of the eye, which is a major determinant in common sight disorders. The most common use of the A-scan is to determine eye length for calculation of intraocular lens power.

Optical Biometry

Optical biometry is the current standard for intraocular lens (IOL) power calculations in clinical practice. Optical biometry is a highly accurate non-invasive automated method for measuring the anatomical characteristics of the eye. Accurate measurements are critical for determining the correct power of an IOL before it is implanted during cataract surgery .

Optical biometry, also known as ophthalmic biometry, using partial coherence interferometry has become the gold standard in ocular biometry as it is highly accurate, easy to perform, non-invasive and comfortable for the patient. The use of optical biometry is a valuable tool when planning cataract surgery and refractive procedures like ICL, resulting in optimization of patient outcomes.