Cataract Biometry – To measure the intra ocular lens power before cataract extraction surgery.
Done by the Zeiss IOL Master device that uses a laser beam to precisely measure the eye structures and calculate the needed IOL for each patient very accurately
also the A-scan Biometry is available which may be needed in some cases.
Biometry of the eye
The measurement of the various dimensions of the eye and of its components and their interrelationships. The axial length and the corneal curvature are essential measurements to predict the correct lens power of an intraocular lens. There are several biometers which are used prior to cataract surgery some based on ultrasound, others on optical systems. A commonly used optical biometry method called partial coherence interferometry (PCI) (e.g. uses infrared laser light and provides a measurement of axial length, lens thickness, anterior chamber depth and corneal curvature). It also includes software for the calculation of an intraocular lens power using a selection of formulae. It is not appropriate for eyes with dense cataracts or severe corneal oedema, in which case ultrasonography is preferable.