[Research progress on intraocular lens power calculation in cataract patients with keratoconus]

Keratoconus (KCN) is a progressive corneal ectasia disorder characterized by thinning and steepening of the cornea. Intraocular lens (IOL) power calculation in cataract patients with KCN often leads to a significant hyperopic prediction error. This is attributable to several factors, including inaccurate keratometry, an altered anterior-to-posterior corneal curvature ratio and erroneous prediction of the effective lens position (ELP). Recent studies have shown that KCN-specific formulas such as the Barrett True-K (BTK) formula and the Kane KCN formula can significantly improve refractive prediction accuracy. This review examines the influence of KCN on IOL power calculations, evaluates the performance of previous formulas in cataract patients with KCN, discusses formula selection strategies based on KCN severity, and systematically summarizes the latest research progress in IOL power calculation, astigmatism correction and IOL power calculation after collagen cross-linking (CXL) for these patients.