Comparison Of Results Of Oculyzer â…¡ And Topolyzer Measure Corneal Topography

Objective:To compare and analyze the difference and consistency of the curvature（K₁,K₂）,astigmatism（Astig）,astigmatism axis（Axis）,average corneal radius of curvature（R_m）and average corneal eccentricity（Ecc）of the anterior corneal surface measured by the Oculyzerâ…¡and Topolyzer corneal topographs,so as to provide references for other clinical applications such as corneal refractive surgery and cataract surgery.Method:A prospective controlled study was used.Collected from September 2019 to August 2020,50 patients（100 eyes）with refractive errors who were planned to undergo FS-LASIK at the Excimer Laser Treatment Center of our hospital,aged 18 to 50,with an average age of 23.65±6.089.,Including 26 males（52%）and 24 females（48%）;Oculyzerâ…¡and Topolyzer were used to measure the curvature（K₁,K₂）,astigmatism（Astig）,and astigmatism axis（Axis）of the cornea,Corneal average radius of curvature（R_m）and corneal average eccentricity（Ecc）,and calculate the average corneal curvature（K_m）,astigmatism vector J₀and J₄₅,use paired t-test to compare the difference of the measurement results,use linear correlation analysis for correlation For sex analysis,Bland-Altman analysis was selected for consistency,and SPSS 23.0 software was used for statistical analysis of the data.The difference was statistically significant at P<0.05.Results:Topolyzer measured the anterior corneal surface curvature K₁value（42.4278±1.2968）D,K₂value（43.6412±1.3778）D,K_mvalue（43.0345±1.2954）D,J₀value（0.5711±0.3605）,J₄₅value（0.0076±0.1775）,Ecc value（0.4493±0.1380）,R_mvalue（7.8570±0.2438）;Oculyzerâ…¡measured the patient’s anterior corneal surface curvature K₁value（42.2448±1.2929）D,K₂value（43.5034±1.4344）D,K_mvalue is（42.8741±1.3213）D,J₀value is（0.5679±0.3763）,J₄₅value is（0.0076±0.2161）,Ecc value is（0.4479±0.1366）,R_mvalue is（7.8877±0.2386）;related by pearson Analysis shows that the r values of K₁,K₂,K_m,J₀,J_45,R_m,and Ecc measured by the two instruments are 0.984,0.985,0.989,0.941,0.747,0.836,0.973respectively;Bland-Altman consistency analysis shows that the two instruments measure the cornea When the curvature is K₁,3%（3/100）of the data fall outside the 95%Lo A,95%Lo A is-0.64～0.27D,the average difference is-0.18D,the two are the largest within the consistency limit The absolute value of the difference is 0.55D;when measuring the corneal curvature K₂,6%（6/100）of the data fall outside the 95%Lo A,the 95%Lo A is-0.63～0.35D,and the average difference is-0.14 D,the absolute value of the maximum difference between the two within the consistency limit is 0.6D;when measuring the corneal curvature K_m,8%（8/100）of the data fall outside the 95%Lo A,and the 95%Lo A is-0.55～0.23D,the average difference is-0.16D,the absolute value of the maximum difference between the two within 95%Lo A is 0.525D;when analyzing the astigmatism vector J₀,5%（5/100）of the data falls In addition to 95%Lo A,95%Lo A is-0.25～0.25D,and the average difference is-0.03D.Within 95%Lo A,the absolute value of the maximum difference between the two is 0.22D;when analyzing the astigmatism vector J₄₅,there is 7%（7/100）of the data fall outside the 95%Lo A,95%Lo A is-0.28～0.28D,the average difference is-0.00002D,the absolute value of the maximum difference between the two within 95%Lo A 0.26D;When measuring R_m,5%（5/100）of the data falls outside the 95%Lo A,95%Lo A is-0.08～0.14mm,and the average difference is 0.03mm,which is within 95%Lo A.The absolute value of the maximum difference is 0.105mm;At Ecc,4%（4/100）of the data fall outside the 95%Lo A,95%Lo A is-0.16～0.15,the average difference is 0.001,the absolute value of the maximum difference between the two within 95%Lo A is 0.155.Conclusion:The results of the curvature and radius of curvature of the anterior corneal surface measured by the two corneal topographs are statistically different,and the measurement results of astigmatism,axial and corneal average eccentricity are not statistically significant;the measured K₁,K₂,K_m,J₀,J₄₅,R_mand Ecc have a high correlation;the measurement K₁,J₀,R_mand Ecc of the two instruments are in good agreement,and other measured values need to be cautious when replacing each other in clinical practice.