三种仪器测量白内障术前角膜生物学参数的比较

目的：比较Pentacam、IOL Master和iTrace三种仪器测量白内障患者术前角膜曲率和散光的测量值的差异。

方法：前瞻性临床研究。收集白内障患者68例82眼，术前均接受IOL Master、Pentacam及 iTrace检查，测量患眼平坦轴角膜曲率(K1)、陡峭轴角膜曲率(K2)、角膜散光及轴向，计算平均角膜曲率(Km)、散光矢量 J0和J45，分析三种仪器测量结果的差异性、相关性和一致性。

结果：三种仪器测量的K1、K2、Km值均无差异(P>0.05)； 三种仪器测量的K1、K2、Km值均呈高度相关(|r|>0.5，P<0.01)，IOL Master与Pentacam、IOL Master与iTrace测量的J0、J45值均呈中度相关(0.3<|r|<0.5，P<0.01)，Pentacam与iTrace测量的J0、J45值均呈低度相关(0.1<|r|<0.3，P<0.05)； Bland-Altman分析法显示三种仪器测得K1、K2、Km、J0、J45一致性差。

结论：Pentacam、IOL Master和iTrace测量角膜曲率及散光之间具有相关性，但一致性差，不可任意替代使用，需根据患者眼部具体情况谨慎选择。

Comparison of three instruments for measuring corneal biological parameters before cataract surgery

AIM: To compare the differences of corneal curvature and astigmatism measured by Pentacam, IOL Master and iTrace of cataract patients.

METHODS:In this prospective clinical trial,68 cataract patients(82 eyes)received treatment at the ophthalmology department of our hospital. In the treatment process, used the IOL Master, Pentacam and iTrace to measure the patient''s corneal curvature(K1, K2, Km)and astigmatism(J0, J45). The difference, correlation and consistence among three instruments were analysed.

RESULTS: Differences analysis showed that in the measurement of K1, K2, Km, there was no difference among Pentacam, IOL Master and iTrace(P>0.05). Pearson correlation analysis showed that K1, K2, Km were highly correlated among three instruments(|r|>0.5, P<0.01). J0, J45 were moderately correlated between IOL Master and Pentacam, so as IOL Master and iTrace(0.3<|r|<0.5, P<0.01). J0, J45 were weakly correlated between Pentacam and iTrace(0.1<|r|<0.3, P<0.05). The Bland-Altman showed that the corneal curvature and astigmatism vectors examined by these three devices had non-comparable results.

CONCLUSION: K1, K2, Km, J0, J45 were correlated among the three devices, but the three devices all cannot directly interchanged, targeted selection is required for the measuring the corneal curvature and astigmatism by these three different instruments in the actual clinical process.