Evaluation of the accuracy of intraocular lens formulae with the inclusion and exclusion of anterior chamber depth measurements

Objectives: This study aims to evaluate and compare the accuracy of the 5 th generation intraocular lens formulae (Barrett Universal II [BU II] and Emmetropia Verifying Optical [EVO] 2.0) with the inclusion and exclusion of anterior chamber depth (ACD) measurements in the Singapore population with medium axial length between 22.0 and 25.99 mm. Materials and Methods: This is a retrospective database study where 485 eyes underwent cataract operation from January 2018 to December 2019 and had their records retrieved for analysis. Results: In this study, the BU II without ACD measurements group had a smaller median absolute error (MedAE) when compared to the BU II with ACD measurements group. Friedman’s test did not reveal a statistically significant difference result for the BU II formula with the inclusion and exclusion of ACD measurements in the calculation for the prediction of residual refractive errors ( p = 0.378). EVO 2.0 without ACD measurements has a smaller MedAE when compared to the EVO 2.0 with ACD measurements group. In this study, Friedman’s test did not reveal a statistically significant difference result for the EVO 2.0 formula with the inclusion and exclusion of ACD measurements ( p = 0.126). Conclusion: This study found that the predicted refractive errors with the inclusion or exclusion of ACD measurements in either the BU II or EVO 2.0 formulae did not prove to be of a difference.