Biometry is the measurement of the eye's physical dimensions. To calculate the correct IOL power, surgeons need two primary measurements:
Historically, was the standard. It used sound waves to measure distance but required physical contact with the eye, which could compress the cornea and lead to errors. Today, Optical Coherence Biometry (like the IOLMaster or Lenstar) is the gold standard. It uses light instead of sound, offering sub-millimeter precision and a non-contact approach that eliminates compression bias. Evolution of IOL Formulas Biometry & IOL Power Calculations - PDF
馃挕 Even a 1mm error in axial length measurement can result in a 2.5 to 3.0 diopter error in the final visual outcome. This highlights why high-precision biometry and modern formulas are non-negotiable for patient satisfaction. Biometry is the measurement of the eye's physical dimensions