Accuracy Of Toric Intraocular Lens Calculations Using Estimated Versus Measured Posterior Corneal Astigmatism

Published 2023 - 41st Congress of the ESCRS

Reference: FP05.02 | Type: Free paper | DOI: 10.82333/x94y-je98

Authors: Maartje Segers* ¹ , Adi Abulafia ² , Valentijn Webers ¹ , Jan-Willem Verstraaten ¹ , Magali Vandevenne ¹ , Tos Berendschot ¹ , Graham Barrett ³ , Rudy Nuijts ¹ , Mor Dickman ¹

¹University Eye Clinic Maastricht,Maastricht University Medical Center+,Maastricht,Netherlands, ²Department of Ophthalmology,Shaare Zedek Medical Center,Jerusalem,Israel, ³Lions Eye Institute,University of Western Australia,Nedlands,Australia

Purpose

To compare the prediction accuracy of toric intraocular lens calculations using estimated versus measured posterior corneal astigmatism (PCA).

Setting

University Eye Clinic, Maastricht University Medical Center+, the Netherlands.

Methods

317 eyes of 317 patients with uncomplicated toric IOL implantation were included in this study. Predicted postoperative refractive astigmatism was calculated with the Barrett Toric calculator using estimated PCA, measured PCA from the Pentacam, and measured PCA from the IOLMaster 700. Astigmatic prediction errors (PE), including their centroid, precision, magnitude and percentage within a certain threshold, were determined using vector analysis and compared between groups.

Results

The Barrett Toric calculator using estimated PCA had a significantly lower median magnitude of the PE than measured PCA from the Pentacam (0.43 vs. 0.48, P<0.01), and a higher percentage of eyes within 0.25D (29% vs. 22%, P=0.03). In a subgroup analysis including 92 eyes with IOLMaster 700 measurements, the Barrett Toric calculator using estimated PCA had a significantly lower median magnitude of the PE than measured PCA from the IOLMaster 700 and the Pentacam (0.31 vs. 0.47 vs. 0.36, P<0.01). The percentage of eyes within a PE magnitude of 0.50D was higher using estimated PCA and measured PCA of the Pentacam compared with measured PCA of the IOLMaster 700 (64% and 66% vs. 53%, P=0.04).

Conclusions

The Barrett Toric calculator using the estimated PCA yielded the most accurate prediction of the postoperative refractive astigmatism compared with the measured PCA in standard clinical practice.