Comparison Of The Accuracy Of Intraocular Lens Power Formulas Of The New Generation After Phacotrabeculectomy

Purpose:To compare the difference between the preoperative theoretical predicted diopters and the actual postoperative diopter of intraocular lens power formulas of the new generation in patients who received trabeculectomy with phacoemulsification and intraocular lens implantation(hereinafter referred to as phacotrabeculectomy).Method:A total of 98 patients(112 eyes)with primary angle-closure glaucoma and cataract who received phacotrabeculectomy in Shandong provincial Hospital from February 2021 to October 2022 were collected,including 75 female patients(82 eyes)and 23 male patients(30 eyes),the mean age was 65.65±8.53 years old.Ocular biological parameters were measured by using IOL Master 700 for all the patients before the surgery.These parameters were calculated by the online calculation formula of Barrett Universal Ⅱ,Kane,EVO 2.0,Pearl-DGS.The preoperative theoretical predicted diopters of various formulas were recorded based on the degree of intraocular lens implanted in previous surgical records.The postoperative spherical equivalence(SE)at 3 months after operation was recorded as the actual postoperative diopter.The postoperative prediction error(PE),mean prediction error(ME),mean absolute prediction error(MAE),median absolute prediction error(MedAE),the percentage of operative eyes when PE in different diopter domains of±0.25D,± 0.50D,±1.00D,±1.50D,±2.00D and the formula performance index(FPI)was calculated and describe the accuracy of the above four formulas in predicting the postoperative diopter of PACG patients who underwent phacotrabeculectomy.Finally,the correlations between the postoperative prediction error of each formula and preoperative intraocular pressure(IOP)and ocular biological parameters were determined by multiple regression analysis.Results:The Kane formula had the lowest mean absolute prediction error and median absolute prediction error values(MAE=0.528,MedAE=0.385),the highest postoperative prediction error percentage of eye number within the diopter domains of±0.5D and the formula performance index(64.3%,FPI=0.379).The Pearl-DGS formula had the highest percentage of eyes within the diopter domains of ± 0.25D(28.6%),the Barrett Universal II formula had the highest percentage of eyes within the diopter domains of±1.0D and ±1.5D(90.5%,95.3%).There was no significantly statistic difference in PE(P=0.764>0.05),MAE(P=0.968>0.05)and MedAE(P=0.79>0.05)of the four formulas.There were significant differences in the percentage of eyes within the diopter domains of±0.5D(P=0.046<0.05).From the multiple regression analysis with PE as the dependent variable,preoperative intraocular pressure and preoperative ocular biological parameters as the independent variables,it was found that PE was positively correlated with preoperative axial length and keratometry in Barrett Universal Ⅱ formula and Pearl-DGS formula;It was negatively correlated with preoperative anterior chamber depth.For Kane and EVO 2.0 formula,PE was positively correlated with preoperative keratometry;It was negatively correlated with preoperative anterior chamber depth.Conclusion:(1)The comprehensive performance of Kane formula is better than that of Barrett Universal Ⅱ formula,EVO 2.0 formula and Pearl-DGS formula in predicting the accuracy of postoperative diopter in PACG patients with cataract who have undergone phacotrabecu lectomy.(2)Axial length,anterior chamber depth and keratometry can directly influence the accuracy for prediction error after phacotrabeculectomy.(3)For different intraocular lens power formulas,the factors affecting the postoperative refractive error and the influence degree of these factors are different.