Ocular biometry is a diagnostic method involving the precise measurement of the anatomical parameters of the eyeball, which are essential for calculating the power of the intraocular lens (IOL) implanted during cataract surgery and for assessing the size and proportions of the eye. The examination involves measuring the anteroposterior axial length of the eyeball, the depth of the anterior chamber, the thickness of the natural lens, the curvature of the cornea (keratometry) and, in some cases, the thickness of the retina and sclera. Modern biometry devices mainly utilise optical biometry technology based on partial optical coherence (PCI) or swept-source OCT, which are characterised by high precision and repeatability of measurements.
The accuracy of biometrics has a direct impact on the final refractive outcome following surgery cataracts, as even minor measurement errors can lead to significant deviations from the intended vision correction. This test is also used in the diagnosis and monitoring of myopia progressive myopia in children, the assessment of eyeball proportions in refractive errors, and in the assessment of suitability for refractive surgery. Modern IOL calculation formulas, such as Barrett Universal II, Hill-RBF and Kane, require precise biometric data to achieve optimal post-operative refractive outcomes.