Update on intraocular lens formulas

Abstract

Purpose of review: This review aims to discuss recent advances in intraocular lens (IOL) power calculation, including newly introduced formulas, classification updates, comparative analyses between formulas, and emerging trends in the field.

Recent findings: A significant number of modern IOL power calculation formulas have become available, incorporating both established and novel concepts such as artificial intelligence and ray tracing. A revised classification system has been introduced, reflecting the underlying principles of each formula. Recent comparative studies demonstrate the excellent refractive outcomes achievable with modern formulas. Emerging trends, such as the use of sum-of-segments axial length and the incorporation of measured posterior corneal data, hold promise for refining predictions in cases of extreme axial lengths and nonphysiological corneas, respectively. Advances in optimization and analytical methods also have the potential to further enhance refractive results.

Summary: The field of IOL power calculation is continually evolving through iterative improvements in formula design, driven by new technologies, advanced instrumentation, and innovative analytical approaches. These advancements enable excellent refractive outcomes, even in atypical eyes.