Comparison of the formulas SRK/T, Hoffer Q, Barrett Universal and HRBF for intraocular lens calculation

Abstract

Objective: Compare the accuracy of the formulas SRK/T, Hoffer Q, Barrett Universal and HRBF for intraocular lens calculation.

Methods: A prospective longitudinal descriptive study was conducted of 70 eyes of 70 patients undergoing cataract surgery with intraocular lens implantation from June 2018 to June 2019 at Ramón Pando Ferrer Cuban Institute of Ophthalmology. In all cases IOL Master 700 was used for lens calculation. Determination of the accuracy of each formula in error prediction of the spherical equivalent was followed by a comparison of the formulas.

Results: Patients aged 60-80 years were 70.00% of the cases; female sex represented 61.43%. Medium sized eyes were 91.43% of the total eyes examined. Mean absolute prediction error did not show any difference between the formulas analyzed for the total range of axial lengths. The Barrett formula spotted 65.71% of the eyes with a prediction error within ± 0.50 D. The highest percentage of eyes with an error greater than 1 diopter corresponded to the Hoffer Q formula (10.00%).

Conclusions: The best represented age group was 60-80 years; female sex prevailed. A predominance was found of medium size and biometric measurements within standard mean values. The formulas HRBF, SRK/T, Hoffer Q and Barrett predict the postoperative refractive result with similar accuracy throughout the total range of axial lengths. The Barrett formula achieves the highest percentage of eyes with postoperative prediction errors within the range of emmetropia.

Key words: Intraocular lens calculation; artificial intelligence; cataract surgery.