Comparison of axial length, anterior chamber depth and corneal curvature parameters obtained from SW-9000 and IOL Master 500 / 国际眼科杂志(Guoji Yanke Zazhi)

ABSTRACT

@#AIM: To compare the differences and agreement in axial length(AL), anterior chamber depth(ACD)flat axial corneal curvature(K1)and steep axial corneal curvature(K2)measured by SW-9000 and IOL Master 500.<p>METHODS: Totally 258 eyes of 129 patients with ametropia were measured with SW-9000 and IOL Master 500. Among them, 159 eyes were low to moderate myopia(-0.75D≤ spherical equivalent <-6D)and 99 eyes were high myopia(spherical equivalent ≥-6D). Comparison between two devices were performed for AL, ACD, K1, and K2. The difference between two instruments were evaluated with a paired samples <i>t</i>-test. The correlation between the measurements was evaluated using Pearson correlation coefficients. The agreement between the devices was evaluated with Bland-Altman plots. <p>RESULTS: There was significant difference between SW-9000 and IOL Master 500 in measuring AL and ACD(all <i>P</i><0.01), but there was no significant difference between K1 and K2 in patients with low to moderate myopia. There was no significant difference in AL, ACD and K1 between SW-9000 and IOL Master 500(all <i>P</i>>0.05), but there was significant difference in K2(<i>P</i><0.05)in patients with high myopia. Pearson correlation analysis showed that AL, ACD, K1 and K2 of patients with low to moderate and high myopia were highly correlated(all <i>P</i><0.01). Bland-Altman consistency analysis showed that the two methods had good consistency in measuring AL in patients with low to moderate and high myopia, but poor consistency in measuring ACD, K1 and K2.<p>CONCLUSION: SW-9000 and IOL Master 500 have good consistency in measuring the AL of people with ametropia. The measurement of ACD and corneal curvature has poor consistency, and should be carefully selected in combination with clinical practice.