ESCRS - FPS04.05 - Measured Corneal Astigmatism Versus Pseudophakic Predicted Refractive Astigmatism In Cataract Surgery Candidates

Measured Corneal Astigmatism Versus Pseudophakic Predicted Refractive Astigmatism In Cataract Surgery Candidates

Published 2022 - 40th Congress of the ESCRS

Reference: FPS04.05 | Type: Free paper | DOI: 10.82333/wxf3-sp27

Authors: Adi Porat Rein 1 , Adi Abulafia* 1 , Graham D. Barrett 2 , Maria Tsessler 1 , David Zadok 1 , Yoav Kan-Tor 3 , Maarten P. Mourits 4 , Ruth Lapid-Gortzak 4

1Ophthalmology,Shaare Zedek Medical Center affiliated with the Hebrew University,Jerusalem,Israel, 2Sir Charles Gairdner Hospital,Perth, WA,Australia;University of Western Australia,WA,Australia, 3the Rachel and Selim Benin School for Computer Science and Engineering,Hebrew University of Jerusalem,Jerusalem,Israel, 4Ophthalmology,Amsterdam UMC,Amsterdam,Netherlands

Purpose

To compare standard and total corneal astigmatism measurements to the predicted pseudophakic (non-toric) refractive astigmatism in candidates for cataract surgery. 

Setting

Ophthalmology Department, Shaare Zedek Medical Center, Jerusalem, Israel.

Methods

A retrospective, cross-sectional study. A single-center analysis of consecutive eyes measured with a SS-OCT biometer at a large tertiary medical center between February 2018 and June 2020.

Corneal astigmatism was calculated based on standard keratometry astigmatism (KA), total corneal astigmatism (TCA) and the predicted refractive astigmatism (PRA) for a monofocal non-toric intraocular lens (IOL) implantation calculated by the Barrett toric calculator using the predicted posterior corneal astigmatism (PRA(Predicted-PCA)) and the measured posterior corneal astigmatism (PRA(Measured-PCA)) options. Separate analyses were performed for OD and OS.

Results

8152 eyes of 5320 patients (4221 OD and 3931 OS) were included in the study. The mean age was 70.6 ± 12.2 years and 54.2% were females. The mean vector values (centroid) for KA, TCA, PRA(Predicted-PCA) and PRA(Measured-PCA) were OD (0.07D@19.5º, 0.27 D @ 7.5º, 0.44D@2.9º and 0.43 D @ 179.3º, respectively, P< .01) and OS (0.02 D @ 150.3º, 0.23 D @ 169.7º, 0.40 D @ 179.4º and 0.42 D @ 169.5º, respectively, P< .01). More than 73% of eyes had a PRA greater than 0.5 D.

Conclusions

Standard and total corneal astigmatism measurements differ significantly from the predicted refractive astigmatism by the Barrett Toric calculator. The PRA, rather than the KA or TCA, should be used as a reference guide for astigmatism correction with toric IOL implantation.