Evaluating newer generation intraocular lens calculation formulas in manual versus femtosecond laser-assisted cataract surgery

AIM:To determine the refractive accuracy of the Haigis,Barrett Universal II(Barrett),and Hill-radial basis function 2.0(Hill-RBF)intraocular lens(IOL)power calculations formulas in eyes undergoing manual cataract surgery(MCS)and refractive femtosecond laser-assisted cataract surgery(Re LACS).METHODS:This was a REB-approved,retrospective interventional comparative case series of 158 eyes of 158 patients who had preoperative biometry completed using the IOL Master 700 and underwent implantation of a Tecnis IOL following uncomplicated cataract surgery using either MCS or ReLACS.Target spherical equivalence(SE)was predicted using the Haigis,Barrett,and Hill-RBF formulas.An older generation formula(Hoffer Q)was included in the analysis.Mean refractive error(ME)was calculated one month postoperatively.The lens factors of all formulas were retrospectively optimized to set the ME to 0 for each formula across all eyes.The median absolute errors(MedAE)and the proportion of eyes achieving an absolute error(AE)within 0.5 diopters(D)were compared between the two formulas among MCS and ReLACS eyes,respectively.RESULTS:Of the 158 eyes studied,64 eyes underwent MCS and 94 eyes underwent ReLACS.Among MCS eyes,the MedAE did not differ between the formulas(P=0.59),however among ReLACS eyes,Barrett and Hill-RBF were more accurate(P=0.001).Barrett and Hill-RBF were both more likely to yield AE<0.5 D among both groups(P<0.001).CONCLUSION:The Barrett and Hill-RBF formula lead to greater refractive accuracy and likelihood of refractive success when compare to Haigis in eyes undergoing Re LACS.