ABSTRACT
This chapter discusses the background of the biometry such as ultrasound biometry and optical biometry. It provides a structured approach to interpreting biometric data. The chapter presents formula for measuring axial length (AL). It examines two methods for the measurement of AL such as the IOLMaster and corneal keratometry. While many intraocular-lens manufacturers have extensive ranges of optics, including monofocal, multifocal, accommodating and toric implants, the first step in identifying the correct implant is to take accurate AL and corneal-curvature measurements. Without these data, it is impossible to predict with any certainty the likely refractive outcome of surgery and, consequently, the benefit of that surgery. Thus, biometry is a key pillar of modern cataract surgery.
