Effect of Posterior Corneal Astigmatism Measured With Different Biometers on Toric IOL Power Calculation

Purpose: To investigate the effect of posterior corneal astigmatism measured with different biometers on toric intraocular lens (IOL) power calculation. Methods: This prospective case series study was conducted at Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China. Patients undergoing measurements by the IOLMaster 700 (Carl Zeiss Meditec AG), CASIA2 (Tomey Corporation), and Pentacam AXL (Oculus Optikgeräte GmbH), uneventful cataract surgery, and toric intraocular lens (IOL) implantation were included. The prediction accuracy of the Barrett toric calculator with predicted and measured posterior corneal astigmatism (Barrett-PPCA and Barrett-MPCA, respectively) was evaluated. Results: A total of 94 patients (94 eyes) were included. Both Barrett-PPCA and Barrett-MPCA with the IOLMaster 700 showed lower median absolute prediction errors (MedAEs) than with the CASIA2 (0.38 to 0.39 vs 0.63 to 0.67 D, both P < .001) and Pentacam AXL (0.38 to 0.39 vs 0.50 to 0.54 D, both P < .05). Similarly, Barrett-PPCA with the Pentacam AXL showed a lower MedAE than with the CASIA2 (0.50 vs 0.63 D, P = .026). There was no significant difference in MedAEs between Barrett-PPCA and Barrett-MPCA for the IOLMaster 700 (0.39 vs 0.38 D, P = .438). Barrett-PPCA showed lower MedAEs than Barrett-MPCA for the CASIA2 (0.63 vs 0.67 D, P = .006) and Pentacam AXL (0.50 vs 0.54 D, P < .001). Conclusions: The IOLMaster 700 exhibited the highest prediction accuracy for toric IOL compared to the CASIA2 and Pentacam AXL. When compared with Barrett-MPCA, Barrett-PPCA yielded comparable prediction accuracy for the IOLMaster 700 and improved accuracy for the CASIA2 and Pentacam AXL.