| Objective To evaluate and compare the accuracy of postoperative refractive calculation by the four kinds of intraocular lens power calculation formulas(SRK/T、Haigis、Holladay、Hoffer Q)with Len Star LS900 optical biometry for high myopia patients with cataract in different axial length and corneal refractive power,so as to provide the basis for high myopia patients with cataract to choose a more appropriate intraocular lens power calculation formula and reserve postoperative refractive outcome in clinic.Methods This research used a retrospective control study.It including62 high myopia patientswith cataract(88 eyes)who undergone phacoemulsification combined with IOL implantation in the department of ophthalmology from April 2016 to January 2017,and the preoperative examination data is complete,the postoperative follow-up data is integrated.They were divided into five groups according to the AL,grouping as follows: the first group,<28.0mm(16eyes);the second,28.0-29.0mm(16eyes);the third,29.0-30.0mm(21 eyes);the fourth,30.0-31.0mm(17 eyes);the fifth,≥31.0mm(18 eyes).They were divided into four groups according to the corneal refractive power.A.<43.0D(20 eyes);B.43.0-44.0D(24 eyes);C.44.0-45.0D(22 eyes);D.≥45.0D(22 eyes).Preoperatively all patients were measured with the contact ultrasound A-scan and Len Star LS900 optical biometry to calculate the axial length,corneal refractive power and other biometric parameters of the eye.According to the different characteristics of each patient,select the appropriate reserve postoperative refractive outcome individually to implant the Bigbag intraocular lens.Put the selected Bigbag intraocular lens degree into the four kinds of intraocular lens power calculation formulas(SRK/T、Haigis、Holladay、Hoffer Q)of Len Star LS900 optical biometry respectively,obtained the each formula reserve postoperative refractive outcome in theory.The patients were followed up after 3 to 6 months postoperatively while the refractive status was stable,and the actual postoperativerefractive outcome was measured for each patient.Record the refractive error and compare the four kinds of intraocular lens power calculation formulas(SRK/T、Haigis、Holladay、Hoffer Q)between the axial length group and the corneal refractive power group by calculating the absolute value of the difference between the preoperative predicted refraction power and the actual postoperative refractive power,that is mean absolute error(MAE).Evaluate the accuracy of the four formulas of Len Star LS900 optical biometry(SRK/T、Haigis、Holladay、Hoffer Q)in cataract patients with high myopia objectively.Results With the increase of the axial length of the eyeswith high myopia,the MAE of each formula increased gradually(P <0.001).But in the same axial length group,the MAE of the four kinds of formulas are not same(P <0.001).The smaller MAE are Haigis and SRK/T,while the larger are Holladay and Hoffer Q in each axial length group.Compare the refractive error of the four kinds of formulas in all the high myopia patients.Therefractive error of Haigis and SRK/Tin the ratio of ±2.00 D reach to 100%,followed by Holladay and Hoffer Q is 96.55%.About the five axial length groups,in group 1,2,3,4 the refractive error of the four kinds offormulas in the ratio of ±2.00 D all reach to 100%,in group 5 therefractive error of Haigis and SRK/Tin the ratio of ±2.00 D reach to 100%,followed by Holladay and Hoffer Q is 83.33%.With the increase of corneal refractive power,there was no significant difference between the MAE of SRK/T、Haigis、Holladay、Hoffer Q(P >0.05).No matter which corneal refractive power group,the smaller MAE are Haigis and SRK/T,the larger are Holladay and Hoffer Q.Conclusion With the increase of the axial lengthin cataract patients with high myopia,the accuracy of each formula was decreased,and the MAE of each formula increased gradually.The Haigisis the most trustworthy and accurate formula for all the groups,the mean absolute error is 0.582±0.304 D.For the cataractpatients with high myopia and long axial length,Haigis and SRK/T have more advantagescompared with Holladay and Hoffer Q.In the cataractpatients with high myopia whose the biological parameters of the eye were measured by Lenstar LS900 optical biometry,we propose to use Haigis or SRK/T to calculate the postoperative refractive power. |
