四种不同方法测量角膜曲率比较研究

Comparison and evaluation of four different techniques of keratometric measurements

目的比较Lenstar与IOL-Master、角膜曲率计及Pentacam在测量角膜曲率（K1、K2）时的差异，分析4种方法的一致性，为Lenstar的临床应用提供依据。方法前瞻性临床研究。对2011年12月至2013年3月在北医三院就诊的患者共纳入受试者84例141只眼，分别应用Lenstar与IOL-Mas-ter、角膜曲率计测试141只眼及Pentacam测试59只眼，测量受试者角膜曲率（K1，K2）值。采用配对t检验对两组测量结果的差异进行比较，不同测量仪器所得数据的相关性采用Pearson相关性分析，两种方法测量结果的一致性采用Bland-Ahman分析。结果Lenstar、IOL-Master、角膜曲率计及Pen-taeam4种仪器的K1测量值分别为（43．59±1．69）D、（43．54±1．73）D、（43．55±1．78）D及（43．30~2．08）D，K2测量值分别为（44．55±1．66）D、（44．61±1．72）D、（44．27±1．74）D及（44．24±2．02）D。Lenstar与角膜曲率计在测量K2时，差异有统计学意义（P〈0．001），其它测量值间分别两两比较，差异均无统计学意义（P〉0．05）。Lenstar与其它3种设备在测量同一参数时均具有高度相关性（r=0．899～0．980，P〈0．001）。Bland-Ahman-致性检验显示，Lenstar与IOL-Master、角膜曲率计及Pen-taeam在测量角膜曲率K1、K2时一致性较差。结论作为一种新型生物测量仪，Lenstar具有简单快捷、非接触等优点。测量角膜曲率时，Lenstar与IOL-Master、角膜曲率计及Pentacam一致性较差，使用中需结合临床意义对仪器的适用范围加以判断。

Objective To compare the corneal curvature （K1, K2） measurements obtained with Lenstar with those measured with IOL-Master, keratometer and Pentacam. Methods In this prospec- tive nonrandomized clinical study, total 141 eyes of 84 subjects were enrolled. K1 and K2 were mea- sured with Lenstar, IOL-Master, keratometer and Pentacam, separately. The differences between two methods were assessed using the paired t test, its correlation was evaluated by Pearson coefficient, and the agreement analysis was performed by Bland-Altman plots. Results K1 value was （43.59±1.69）D, （43.54±1.73）D, （43.55±1.78）D and （43.30±2.08）D, and K2 value was （44.55±1.66）D, （44.61±1.72）D, （44.27±1.74）D and （44.24±2.02）D based on Lenstar, IOL-Master, keratometer and Pentacam, respective- ly. All comparisons showed a non-significant difference, except for the comparison of K2 measure- ments using the Lenstar and keratometer （P 〈0.001）. All biometry measurements revealed good linear correlation （r =0.899-0.980, P 〈0.001）. The Bland-Altman showed that the four devices had non-compa- rable results for corneal curvature measurement. Conclusions Lenstar can provide noncontact biometry measurements easily and safely, which are welcome by patients. It is important to note in clinical prac- tice, that corneal curvature values acquired by these devices are not directly interchangeable.