Comparison Of The Accuracy Of Intraocular Lens Power Calculation FormulaswithA1-UV Intraocular Lens

Part Ⅰ Comparison of the accuracy of 7intraocular lens power calculation formulas with A1-UV IOL in different axial length and anterior chamber depthObjective:To compare the accuracy of 7 intraocular lens power calculation formulas SRK/T,Hoffer Q,Holladay 1,Haigis,Barrett universal II,Kane and EVO in predicting the refractive power of cataract patients implanted with A1-UV intraocular lens（IOL）in different axial length and anterior chamber depth,and to analyze the prediction error,and explore the relevant factors affecting the accuracy of IOL refractive power prediction.Methods:Prospective cohort study.Patients who underwent phacoemulsification and implantation of A1-UV IOL in the Affiliated Hospital of North Sichuan Medical College from March to October 2021 were included.The ocular biological parameters were measured by IOLMaster 700 before operation,and the axial length（AL）,anterior chamber depth（ACD）,keratometry readings（K）,white to white（WTW）,lens thickness（LT）and central corneal thickness（CCT）were recorded.According to theaxial length of ocular axis and the anterior chamber depth,patientswere divided into axial length group and anterior chamber depthgroup.The axial length group was divided into:short axial length group,AL≤22.00mm（60 eyes）;In normal axial length group,22.00mm<AL<26.00mm（210 eyes）;In the long axial length group,AL≥26.00mm（100 eyes）.The anterior chamber depth group was divided into:shallow anterior chamberdepth group,ACD≤3.00mm（163 eyes）;In normal anterior chamber depthgroup,3.00mm<ACD<3.50mm（136 eyes）;In the deep anterior chamber depth group,ACD≥3.50mm（71 eyes）.Use the built-in lens manager of IOLMaster 500 to optimize the IOL constant,and use SRK/T formula to select the appropriate IOL degree according to the needs of patients.The patients were followed up regularly after operation.According to the subjective refraction results of 3 months after operation,the accuracy of 7 formulas SRK/T,Hoffer Q,Holladay 1,Haigis,Barrett universal Ⅱ,Kane and EVO in predicting the refractive power of Al-UV IOL under different axial length and different anterior chamber depth was compared,and the relationship between the mean error（ME）of different IOL calculation formulas and ocular biological parameters was analyzed.Result:A total of 370 patients（370 eyes）with cataract were included in the study.All patients were calculated with 7IOL formulas,among which the highest formula performance index（FPI）was EVO formula（0.579）,followed by Kane formula（0.555）.The difference of absolute error between the 7 IOL calculation formulas was statistically significant（χ²=357.942,P<0.001）,in which the median absolute error（MedAE）of Barrett universal II and EVO formula is the smallest（0.23D）;The mean absolute error（MAE）of Kane and EVO formulas is the smallest（0.27D）.The difference of absolute prediction error of IOL calculation formula between different axial length groups was statistically significant（χ²=46.145,141.264,213.010,P<0.001）.In the short axial length group,the FPI of Kane formula was the highest（0.335）,and the MedAE and MAE of Kane formula were the lowest（0.45D,0.44dD;In the normal axial group,the FPI of Barrett universal Ⅱ was the highest（0.648）,the MedAE of Barrett universal Ⅱ and Kane formula was the lowest（0.17D）,and the MAE of Barrett universal Ⅱ formula was the lowest（0.19D）;In the long axial length group,the FPI of Kane formula is the highest（0.521）,the MedAE of Kane and EVO formula is the lowest（0.28D）,and the MAE of Kane and EVO formula is the lowest（0.3 1D）.The difference of absolute prediction error of IOL calculation formula between different anterior chamber depth groups was statistically significant 211.923,90.716,67.705,P<0.001）.In the shallow anterior chamber depth group,the FPI of Kane formula was the highest（0.519）,the MedAE of Barrett universal Ⅱ formula was the lowest（0.26D）,and the MAE of EVO formula was the lowest（0.20D）;In the normal anterior chamber depth group,the FPI of Barrett universal Ⅱ was the highest（0.580）,the MedAE of Kane and EVO formula was the lowest（0.21D）,and the MAE of EVO formula was the lowest（0.24D）;In the deep anterior chamber depth group,the FPI of Kane formula was the highest（0.600）,the MedAE of EVO formula was the lowest（0.18D）,and the MAE of Kane formula was the lowest（0.23D）.The ME of SRK/T formula was significantly positively correlated with AL,ACD and WTW（R²=0.367,0.144,0.070,P<0.05）,and negatively correlated with the average corneal curvature（Km）（R²=0.058,P<0.05）.There was a significant positive correlation between ME of Hoffer Q formula and AL,ACD and WTW（R²=0.707,0.308,0.043,P<0.05）.The ME of Holladay 1 formula was significantly positively correlated with AL,ACD and WTW（R²=0.700,0.260,0.055,P<0.05）,and negatively correlated with Km（R²=0.012,P<0.05）.There was a significant positive correlation between ME of Haigis formula and AL,ACD,LT and WTW（R²=0.507,0.105,0.105,0.023,P<0.05）.The ME of Barrett universal Ⅱ was significantly positively correlated with AL,ACD,WTW and CCT（R²=0.024,0.070,0.016,0.012,P<0.05）,and negatively correlated with LT（R²=0.022,P<0.05）.The ME of Kane formula was significantly positively correlated with ACD（R²=0.022,P<0.05）and negatively correlated with LT（R²=0.018,P<0.05）.The ME of EVO formula was significantly positively correlated with A1（R²=0.036,P<0.05）.Conclusion:1.In normal AL group and ACDgroup,7 IOL calculation formulas have good accuracy in predicting the diopter of A1-UV intraocular lens.In abnormal AL group and ACDgroup,Barrett universal Ⅱ,Kane and EVO formulas have high accuracy in predicting the refractive power of A1-UV intraocular lens2.Barrett universal II,Kane and EVO formulas are less affected by the changes of ocular biological parameters.The 3 IOL calculation formulas are more stable and the prediction accuracy are higher.Part ⅡComparison of theaccuracy of different intraocular lens power calculation formulas and axial length optimization formulas in long eyesObjective:To compare the accuracy of SRK/T,Hoffer Q,Holladay 1,Haigis,Barrett universal Ⅱ,Kane and EVO and their corresponding Wang-Koch axial length optimization formula in long eyes.Methods:Prospective cohort study.Patients with long axial length cataract who underwent phacoemulsification and implantation of A1-UV IOL in the Affiliated Hospital of North Sichuan Medical College from March to October 2021 were included.Use the built-in IOL optimization constant of IOLMaster 500,and use SRK/T formula to select the appropriate IOL degree according to the needs of patients.The patients were followed up regularly after operation.According to the subjective refraction results of 3 months after operation,the accuracy of IOL diopter calculation in patients with long axis cataract was compared between 7 formulas（SRK/T,Hoffer Q,Holladay 1,Haigis,Barrett universal Ⅱ,Kane and EVO）and the corresponding Wang-Koch axial length optimization formula.Result:A total of 100 patients（100 eyes）with long axial length cataract were included in the study.All patients used 7 formulas SRK/T,Hoffer Q,Holladay 1,Haigis,Barrett universal Ⅱ,Kane,EVO,and the corresponding Wang-Koch axial length optimization formula,including the original version of axial length optimization formula SRK/T _W-K,Hoffer Q_W-K,Holladay 1_W-K,Haigis_W-K,and the modified versionaxial lengthoptimization formula SRK/T_{Modified W-K},Holladay 1 _{Modified W-K}.In the comparison of 13 different calculation formulas,Kane formula（0.521）has the highest FPI,followed by Holladay 1 _{Modified W-K} formula（0.424）.The difference of absolute prediction error between 13 IOL calculation formulas was statistically significant（χ²=254.849,P<0.001）.The MedAE of Kane and EVO formula is the smallest（0.28D）,followed by Barrett universal Ⅱ formula（0.29D）.The MAE of Kane and EVO formula is the smallest（0.31D）,followed by Barrett universal Ⅱformula（0.34D）.Kane formula me has the highest percentage of eyes within± 0.25D refractive threshold（47.00%）;The proportion of ME in Kane and EVO formula within ± 0.50D and± 0.75D is the highest（82.00%,95.00%）;The proportion of me in EVO formula within ± 1.00D is the highest（100.00%）.Conclusion:1.SRK/T,Hoffer Q,Holladay 1,Haigis formula with Wang-Koch axial length optimization,the occurrence of postoperative hyperopiais significantlyreduced,and the prediction accuracy is improved.2.The original version of axial length optimization formula SRK/T _W-K,Hoffer Q_W-K,Holladay 1_W-K,Haigis_W-K have different degrees of postoperative myopia,while the modified version of axial length optimization formula SRK/TModified_W-K,Holladay 1 _{Modified W-K} avoid excessive optimization of ocular axis and show higher prediction accuracy than the original version.3.Barrett universal Ⅱ,Kane,EVO,SRK/T_{Modified W-K},Holladay 1 _{Modified W-K} have high prediction accuracy in long eyes.