iTrace波前像差仪表达眼屈光状态的临床研究

Clinical study of refractive status expressed by the iTrace wavefront aberrometer in myopia

目的研究iTrace波前像差仪在单眼闭合式和双眼开放式两种状态下，客观验光表达近视患者屈光状态的准确性。方法对前瞻性研究近视患者39例77只眼，球镜-0．75～9．50D，柱镜0．00—2．50D。以主觉验光（综合验光仪标准流程）作为标准，主觉验光和iTrace波前像差仪单眼闭合式（iTrace单眼）和双眼开放式（iTrace双眼），客观验光之间的差值作为衡量iTrace波前像差仪客观验光准确性的指标。用矢量分析法分析验光结果。分别计算主觉验光、iTrace单眼验光和iTrace双眼验光之间的矢量差值和绝对屈光度差值（m值），再把矢量差值的平均值转换成球镜、柱镜和轴向差值的形式。结果iTrace单眼验光和主觉验光比较，球镜、柱镜和轴向差值分别为：-0．02D、-0．25D和74．81度，m值的平均值为（0．53±0．31）D，其中m值小于0．75D的占81．82％；iTrace双眼验光和主觉验光比较，球镜、柱镜和轴向差值分别为：-0．27D、-0．20D、67．46度，m值的平均值为（0．56±0．29）D，其中m值小于0．75D的占75．32％；iTrace单眼验光和iTrace双眼验光与主觉验光比较，m值小于0．75D所占的百分比之间差异无统计学意义（P〉0．05）。结论iTrace波前像差仪能客观表达人眼的屈光状态，其结果能为主觉验光提供参考，但欲以iTrace单眼验光或iTrace双眼验光替代主觉验光尚有诸多问题有待解决。

Objective To investigate the accuracy of objective refractive status measured by iTrace aberrometer in two ways （single eye closed field and binocular open field）. Methods 77 myopic eyes of 39 patients with refractive error ranged fi＇om-0.75 to-9.50 diopters （D） for sphere, 0 to-2.50 D for cylinder. Manifest refraction （MR） was used as the standard, the accuracy was defined as the difference among MR and that of the iTrace single eye closed field refraction and binocular open field refraction. The results were analyzed using power vector analysis. The vector error and absolute dioptfic error （m） were computed, and then the mean vector error was converted to spherocylindrical power errors. Results The sphere-cylinder-axis error between MR and the iTrace single eye closed field refraction was-0.02D,-0.25D , 74.81° , respectively, and mean value of m was （0.53±0.31 ）D with 81.82 % eyes within 0.75D. The sphere-cylinder-axis error between MR and the iTrace binocular open field refraction was-0.27D,-0.20D, 67.46°, respectively, and mean value ofm was （0.56±0.29）D with 75.32% eyes. There was no significant difference between 81.82% and 75.32%ofm value within 0.75D （P〉0.05）. Conclusions The iTrace wavefi＇ont aberrometer could objectively express refrac- tive status in myopia, and as a reference of MR. There were many questions need to be solved if iTrace single eye closed field refraction or binocular open field refi＇action expected to replace the MR.