Comparison Of Thecorneal Curvature And Astigmatism Measurement Before Cataract Surgery Withfour Kinds Of Instruments

Purpose:The differences and consistency of the measurement of corneal curvature and astigmatism by IOL-Master500,automatic keratoptometry KR-8900,pentacam three-dimensional anterior segment analyzer and OPD-Scan ? wavefront aberration instrument were analyzed and compared,so as to better guide clinical application.Methods:Prospective study,52 eyes of 31 patients with cataract phacoemulsification intraocular lens implantationwere collected during August 2018 to September 2018 in the First Affiliated Hospital of Guangxi Medical university.There were 24 males?40 eyes?and 7 females?12 eyes?andat 17 to 88?average 62.55±13.50?years old years old.Four instruments including IOL-Master500,automatic cornea Curvature refractometer KR-8900,pentacam three-dimensional anterior segment analyzer,OPD-Scan ? wavefront aberrometer measure and record the preoperative corneal curvature K₁,K₂,astigmatism and astigmatism axis of cataract patients,calculate Km J₀,J₄₅5 and degree of intraocular lens,the difference was compared by paired t test,the correlation was analyzed by linear correlation,and the consistency was analyzed by Bland-Altman.Results:1.The difference of corneal curvaturefor K₁between KR-8900 and OPD-Scan ? was statistically significant?P<0.01?,and the rest were not statistically significant.The difference of corneal curvaturefor K₂ between IOL-Master and Pentacam,IOL-Master and OPD-Scan ? were statistically significant?P<0.01?,and the rest were not statistically significant.As for thecorneal curvaturefor K_m,IOL-Master and Pentacam,IOL-Master and OPD-Scan ?,KR-8900 and Pentacam,KR-8900 and OPD-Scan ? were statistically significant?P<0.05?,and the rest were not statistically significant.When analyzing the degree of intraocular lens,the difference between OPD-Scan ? and IOL-Master?KR-8900 was statistically significant?P<0.01?.There were no statisticallysignificance.According to the pearson correlation analysis,there was a high correlation between all of the instruments when measuring K1,K2,and Km?r=0.940⁰.988,P<0.001?.When analyzing the degree of intraocular lens,there was a high correlation between the instruments?r=0.997⁰.999,P=0.000?.In the Bland-Altman scatter plot,the maximum range of K1,K2,and K_m 95%LoA is-1.11D¹.18D,-0.98D¹.21D,-0.88D⁰.89D,which exceeds the clinically acceptable range,so the consistency is poor.However,the 95%LoA of the intraocular lens has a maximum range of-0.77 to 0.69D,and the maximum range is narrow so the consistency is good.2.There was no significant difference between the two pairs of all instruments when measuring J₀?p>0.05?.There was no significant difference between the two pairs of all instruments when measuring J₄₅?p>0.05?.When Pearson correlation analysis vector J₀,IOL-Master andPentacam?OPD-Scan ?revealed linear correlation?P<0.05?;and the vector J₄₅,Pentacam and IOL-Master?OPD-Scan ? revealed linear correlation?P<0.05?,there were no statistical significance between the remaining instruments.In the Bland-Altman scatter plot,the maximum range of J₀95%LoA was-2.0².1D,the maximum range of 95%LoA waswas a relatively large,this was beyond the clinically acceptable range of values,so the consistency was poor.When analyzing J₄₅,the maximum range of 95%LoA was-1.23 to 1.18D,the maximum range of 95%LoA was a relatively large,this was beyond the clinically acceptable range,so the consistency is poor.Conclusions:1.The difference of the IOL-Master and KR-8900,pentacam and OPD-Scan ?were small in the measurement of corneal curvature.The difference of the remaining instruments was large,and the consistency of the all instruments in pairswas poor.Curvature In calculating the degree of intraocular lens,IOL-Master and KR-8900,IOL-Master and pentacam,KR-8900 and pentacam,pentacam and OPD-Scan ? have small differences,all instruments have good agreements,so they could be replaced each other in clinical.2.The difference of the four instruments in the measurement of corneal astigmatism were small,but agreementswere so poor,the four instrumentsshould be used based on the working principle and focus in guiding the clinical application.