Advances in the correlation between the angle kappa and the implantation of multifocal intraocular lenses

Abstract

Cataract is the most prevalent blindness-inducing human eye disease. Cataract extraction combined with intraocular lens (IOL) implantation has become the main surgical method for cataract treatment. With the continuous development of surgical techniques and the emergence of new types of IOL, cataract surgery has transitioned from simply restoring vision to correcting refractive errors and presbyopia. Multifocal intraocular lenses (MIOLs) can effectively meet patients' needs for distance, intermediate, and near vision. While the types and designs of MIOLs have been continuously enriched, the clinical outcomes of their implantation are still affected by various factors, the angle kappa being among the most important. This review aims to introduce angle kappa, including its definition and measurement methods, as well as the mechanisms by which it influences visual quality. It will explore the characteristics of various types of MIOLs and summarize the correlation between angle kappa and postoperative visual quality based on clinical studies. Precise preoperative measurement of angle kappa and selection of an appropriate type of IOL based on its size, are important for optimizing postoperative visual quality. In the future, research should focus on developing more precise measurement tools and on optimizing the design of IOLs to enhance their adaptation to the angle kappa.