Comparison of Hill-RBF 3.0 with Barrett Universal II, SRK/T, Hoffer Q, Haigis, and Holladay 1 to predict the accuracy of post-cataract surgery refractive outcomes in Indian eyes

Purpose: To compare Hill-RBF 3.0 with Barrett Universal II (BU II), SRK/T, Hoffer Q, Haigis, and Holladay 1 in predicting the accuracy of post-cataract surgery refractive outcomes in Indian eyes. Methods: In this prospective, comparative, observational study, consecutive patients with uncomplicated age-related cataracts undergoing uneventful phacoemulsification with posterior chamber intraocular lens (IOL) implantation were included. The mean absolute errors (MAEs) and median absolute errors were used to determine the accuracy of predicted postoperative target refractions. Results: A total of 219 eyes of 173 patients were enrolled. Based on the axial lengths (AL), the patients were classified into: AL 24.5 mm (long). BU II exhibited the lowest MAE for normal ALs (0.2683 ± 0.2790 D) as well as for the entire population (0.2764 ± 0.2764 D). For the short ALs, Hill RBF 3.0 exhibited the lowest MAE (0.3268 ± 0.3268 D), while for the long ALs, SRK/T showed the lowest MAE (0.2823 ± 0.2642 D). BU II exhibited the highest percentage of eyes of 57.5%, 95.4%, and 98.6% within ±0.25, ±0.75, and ±1.0 D of postoperative target refractions respectively, whereas Hill RBF 3.0 had the highest percentages of eyes (88.1%) within ±0.5 D of postoperative target refraction. Conclusion: Hill-RBF 3.0 exhibited the least MAE for patients with short ALs, while BU II showed the least MAE for normal ALs as well as for the entire population and SRK/T for long ALs. This study is likely to aid surgeons in selecting the most appropriate IOL power formula, which thereby improves the refractive outcomes with utmost accuracy.