Comparison of central corneal thickness measured by different instruments

Abstract:

AIM:To compare the differences of central corneal thickness (CCT) measured by optical bio-measurement, Wavelight anterior segment analyzer, Galilei anterior segment analyzer, optical coherence tomography (OCT) and A-mode ultrasonic pachymeter(USP).METHODS:All 74 cases (147 eyes) with myopia were examined before refractive surgery with more than five kinds of instruments respectively, the results were compared with USP. RESULTS:CCT measured by USP was 537.52±3154μm, 535.32±29.74μm by the optical bio-measurement, which was 2.20±7.29μm less than USP（t=3.67,P<0.01）. CCT was 542.51±30.21μm by Wavelight, which was 4.99±10.45μm more than USP（t=-5.79,P<0.01）. CCT was 546.48±27.38μm by Galile, which was 895±10.44μm more than USP（t=-10.40,P<0.01）. CCT was 530.33±28.61μm by OCT, which was 7.20± 7.69μm less than USP（t=11.35,P<0.01）. There were significantly statistical differences between these four methods and USP.CONCLUSION:On CCT measurement, there is difference between 4 types of instruments and A scan measurement outcome. They can not instead each other, but as raference.