自动角膜曲率计与角膜地形图仪测量儿童角膜屈光力的比较研究

Comparison of automatic keratometry and corneal topography on children＇ corneal power

目的比较KR-8100自动角膜曲率计与TMS-4角膜地形图仪测量屈光不正儿童角膜屈光力及散光轴向的差异，并对两种测量方法进行一致性评价。方法采用KR-8100自动角膜曲率计及TMS-4角膜地形图仪对53例（106只眼）屈光不正儿童进行测量，应用配对t检验对两种方法测量的陡峭子午线角膜屈光力（Ks）、平坦子午线角膜屈光力（Kf）、角膜散光Ks-Kf大小及轴向进行比较，并应用Bland—Altmann分析对两种测量方法进行一致性评价。结果角膜地形图仪测量的Ks、Kf、Ks—Kf值均高于角膜曲率计的测量值（P〈0．01）；角膜地形图仪与角膜曲率计的散光轴向测量值差异有统计学意义（P〈0．01）。两种仪器测量Ks的差值的均数为1．72D，测量Kf的差值的均数为1．37D，这种测量差别临床上不能接受，说明两种仪器测量角膜屈光力的一致性较差。结论KR-8100自动角膜曲率计与TMS-4角膜地形图两种测量方法在临床上不能替代使用。

Objective To evaluate the agreement of measuring corneal power and astigmatism axis between automatic keratometry and corneal topography on ametropia＇ children.Methods Keratometric reading with Topcon KR-8100 automatic keratometry and corneat topography with the TMS-4 on 53 ametropia＇ children, 106 eyes were compared.Difference in measurements of steep meridian power magnitude Ks, fiat meridian power magnitude Kf, astigmatism magnitude Ks-Kf and location as well between the two methods were assessed using paired t test.Bland-Altmann method was used to evaluate the agreement of the two methods.Results The Ks、Kf、 Ks-Kf of the corneal topography were higher than that .ofihe keratometry＇ （P 〈0.01 ）.The difference of the astigmatism axis between the corneal topography and the keratometry was significant （P 〈0.01 ）.Of the two instruments,the mean difference of Ks was 1.72D,Kf was 1.37D,the difference of the measurement cannot be acceptable, so it showed incomparable results for them to measure the Corneal power.Conclusions The Topcon KR-8100 automatic keratometry and the TMS-4 corneal topography can not be considered as interchangeable.