Improving the Accuracy of Lens Formulas for in-the-bag Intraocular Lens Implantation in Marfan Syndrome Patients with Ectopia Lentis

Xin Shen; Zexu Chen; Wannan Jia; Yalei Wang; Xinyao Chen; Tianhui Chen; Yan Liu; Linghao Song; Qiuyi Huo; Yongxiang Jiang

doi:10.1097/j.jcrs.0000000000001592

Improving the Accuracy of Lens Formulas for in-the-bag Intraocular Lens Implantation in Marfan Syndrome Patients with Ectopia Lentis

J Cataract Refract Surg. 2024 Dec 12. doi: 10.1097/j.jcrs.0000000000001592. Online ahead of print.

Authors

Xin Shen^{1

2}, Zexu Chen^{1

2}, Wannan Jia^{1

2}, Yalei Wang^{1

2}, Xinyao Chen^{1

2}, Tianhui Chen^{1

2}, Yan Liu^{1

2}, Linghao Song^{1

2}, Qiuyi Huo^{1

2}, Yongxiang Jiang^{1

2}

Affiliations

¹ Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai 200031, China.
² Key laboratory of Myopia and Related Eye Diseases, NHC; Key laboratory of Myopia and Related Eye Diseases, Chinese Academy of Medical Sciences, Shanghai, 200031, China.

PMID: 39663600
DOI: 10.1097/j.jcrs.0000000000001592

Abstract

Purpose: To improve the accuracy of intraocular lens (IOL) power calculation formulas by modifying the effective lens position (ELP) equations for patients with Marfan Syndrome (MFS) and ectopia lentis (EL) undergoing in-the-bag IOL implantation.

Setting: Eye and ENT Hospital of Fudan University.

Design: Retrospective cohort study.

Methods: The formula-specific ELP was obtained from the SRK/T, T2, Holladay I, and HofferQ formulas. The back-calculated ELP was obtained based on the vergence formula using preoperative biometry, postoperative refraction, and the IOL power. The Generalized Linear Models or Gradient Boosting Machines were used to predict ELP or ELP error.

Results: A total of 255 patients (255 eyes) were assigned randomly into a training set and a validation set (7:3 ratio). Linear correlation identified axial length(AL), corneal height, and white-to-white as predictors for ELP and ELP error for patients with shorter AL (AL ≤ 24 mm). For those with longer AL (AL > 24 mm), AL and the central corneal radius were identified as the primary predictors. Incorporating these predictors into the modified ELP formula significantly improved the accuracy in the validation set, including SRK/T, T2, Haigis, Holladay I, and HofferQ formulas. The improvement was more pronounced in patients with shorter AL. Additionally, the GLM-modified formulas outperformed both the Barrett Universal II and Kane formulas. The accuracy across different ocular dimensions was comparable among the modified formulas, based on which an online calculator was developed.

Conclusions: Using the more accurately predicted ELP can significantly improve the accuracy of existing formulas in patients with MFS.