显微定量角膜检查镜准确性的评价

Evaluation of the accuracy of a new quantitative keratoscope for measuring astigmatism

目的评价一种新型的显微定量角膜检查镜在测量正常人眼角膜散光方面的准确性和可重复性。方法两名独立的观测者对44名正常人进行显微定量角膜检查镜的散光测量,并将结果与角膜曲率计、角膜地形图进行比较。同时评估角膜镜测量的组内变异和组间变异。结果角膜镜1环的测量结果与角膜曲率计(t=-0.673,P=0.503)和角膜地形图(t=1.098,P=0.276)有很好的一致性。而2、3环的测量值与曲率计测量值比较有较显著的差异。角膜镜测量的组间变异(COR=0.4270)显示角膜镜在正常人眼散光测量中有较好的可重复性。结论显微定量角膜检查镜是一种简便、实用、具有较好准确性和可重复性的散光测量仪器。

Objective To evaluate the accuracy and reliability of a new quantitative keratoscope for use on normal people. Methods Astigmatic readings were obtained with the new keratoscope, a keratometer and a topographer by two independent examiners on 44 normal people. The readings from the new keratoscope were compared to readings from the other two instruments and inter-and intra-observer coefficients of variability （CV） were assessed. Results The readings of the first ring using the keratoscope were found to have good consistency with both the keratometer （t=-0.673,P=0.503） and the topographer （t=1.098, P=0.276）. However, significant differences were found between the readings of the second （or third） ring using the keratoscope and keratometer. The keratoscope showed good reliability in assessing the magnitude of astigmatism with an inter-observer CV of 0.4270. Conclusion The new quantitative keratoscope is a simple and useful instrument for use as an adjunct to clinical practice that requires little experience to take accurate measurements of corneal astigmatism.