Accuracy of Total Corneal Power Calculation for Multifocal Toric Intraocular Lens Implantation: Swept-Source OCT-Based Biometer vs Scheimpflug Tomographer.

Abstract

To evaluate the accuracy of total corneal power calculation from a swept-source optical coherence tomography-based biometer and a rotating Scheimpflug tomographer for the Acrysof IQ Panoptix toric TFNT intraocular lens (IOL) (Alcon Labroatories, Inc). A retrospective study was undertaken on 145 eyes implanted with the TFNT IOL. The accuracy of total corneal power calculation from a SS-OCT-based biometer (IOLMaster 700; Carl Zeiss Meditec AG; total keratometry [TK]) and a rotating Scheimpflug tomographer (Oculus Optikgeräte GmbH; total corneal refractive power at 3 mm [TCRP3] and at 4 mm [TCRP4]) were compared. The surgically induced astigmatism vector, difference vector, angle of vector, correction index, index of success, coefficient of adjustment, and flattening index were analyzed using the VectrAK analysis program (ASSORT). The index of success showed a significant difference between the three methods (P = .035, analysis of variance test). The mean ± standard deviation of the index of success was the best in TK (0.43 ± 0.20), followed by TCRP4 (0.47 ± 0.24, P = .400, Bonferroni HSD test) and TCRP3 (0.50 ± 0.22, P = .030, Bonferroni HSD test). The preoperative refractive astigmatism prediction error was within ±0.50 diopters (D) in 62 eyes (42.8%) when using TCRP4 and in 66 eyes (45.5%) when using TK. These study results suggest that the refractive accuracy of TFNT implantation using total corneal power from TCRP4 and TK was favorable. [J Refract Surg. 2021;37(10):686-692.].