How To Predict Corneal Power Vectors From Preoperative Iolmaster 700 Keratometry And Total Corneal Power In Toric Iol Implantation
Published 2025 - 43rd Congress of the ESCRS
Reference: FP13.14 | Type: Free paper | DOI: 10.82333/xz4s-n848
Authors: Waseem Nasser* 1 , Adir Sommer 1 , Margarita Safir 2 , Dror Ben Ephraim Noyman 1 , Tzahi Sela 3 , Gur Munzer 3 , Igor Kaiserman 4 , Eyal Cohen 5 , Michael Mimouni 6
1Ophthalmology,Rambam Health Care Campus,Haifa,Israel;Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology,Haifa,Israel, 2Ophthalmology,Rabin Medical Center,Petah Tikva,Israel;Ophthalmology,Sackler School of Medicine,Tel Aviv,Israel, 3Care-Vision Laser Center,Tel Aviv,Israel, 4Care-Vision Laser Center,Tel Aviv,Israel;Ophthalmology,Barzilai Medical Center,Ashkelon,Israel;Faculty of Health Sciences, Ben-Gurion University of the Negev,Beer Sheba,Israel, 5Sackler School of Medicine, Tel Aviv University,Tel Aviv,Israel;Care-Vision Laser Center,Tel Aviv,Israel;Ophthalmology,Tel Aviv Sourasky Medical Center,Tel Aviv,Israel, 6Ophthalmology,Rambam Health Care Campus,Haifa,Israel;Ruth and Bruce Rappaport Faculty of Medicine, Technion - Israel Institute of Technology,Haifa,Israel;Care-Vision Laser Center,Tel Aviv,Israel
Purpose
The purpose of this study is to compare the reconstructed corneal power (RCP) by working backwards from the post-implantation spectacle refraction and toric intraocular lens power and to develop the models for mapping preoperative keratometry and total corneal power to RCP.
Setting
Retrospective single-centre study
Methods
Retrospective single-centre study involving 442 eyes treated with a monofocal and trifocal toric IOL (Zeiss TORBI and LISA). Keratometry and total corneal power were measured preoperatively and postoperatively using IOLMaster 700. Feedforward neural network and multilinear regression models were derived to map keratometry and total corneal power vector components (equivalent power EQ and astigmatism components C0 and C45) to the respective RCP components.
Results
Mean preoperative/postoperative C0 for keratometry and total corneal power was -0.14/-0.08 dioptres and -0.30/-0.24 dioptres. All mean C45 components ranged between -0.11 and -0.20 dioptres. With crossvalidation, the neural network and regression models showed comparable results on the test data with a mean squared prediction error of 0.20/0.18 and 0.22/0.22 dioptres2 and on the training data the neural network models outperformed the regression models with 0.11/0.12 and 0.22/0.22 dioptres2 for predicting RCP from preoperative keratometry/total corneal power.
Conclusions
Based on our dataset, both the feedforward neural network and multilinear regression models showed good precision in predicting the power vector components of RCP from preoperative keratometry or total corneal power. With a similar performance in crossvalidation and a simple implementation in consumer software, we recommend implementation of regression models in clinical practice.