keratometria
Keratometry, also known as keratometria, is the measurement of the curvature of the anterior surface of the cornea. It provides an estimate of the corneal refractive power and is commonly expressed in diopters. Keratometry converts the radius of curvature into diopters using the standard formula with an assumed corneal refractive index, typically around 1.3375. In practice, keratometric power is calculated as P = (n − 1) / r, with r in meters, resulting in values that usually fall in the low 40s to mid-40s diopters range for a normal central cornea.
Measurements are taken along the flattest (K1) and steepest (K2) meridians, yielding the magnitude of corneal
Keratometry is performed with manual keratometers or automated devices, and many modern systems integrate keratometry with
Applications of keratometry include fitting contact lenses, especially rigid gas-permeable lenses, and planning refractive surgical procedures
Limitations include its focus on the anterior surface, reliance on a fixed index, and susceptibility to tear