AIM: To investigate the differences in central corneal thickness(CCT)measurements using pachymetries of ultrasound and Schempflug system.

METHODS: The CCT of 150 healthy corneal eyes(from 86 cases)were measured with non-contact tonometry/pachymetry NT-530P, Pentacam and ultrasonic pachymetry. The consistency of the measurements was statistically analyzed by one-way ANOVA and Bland-Altman plot. The differences were analyzed by Pearson correlation coefficients.

RESULTS: The CCT values measured with non-contact tonometry/pachymetry NT-530P, Pentacam and ultrasonic pachymetry were(541.19±32.47)μm,(542.76±32.40)μm and(539.88±31.98)μm, respectively. No statistically significance differences were found among the three instruments(F=0.290, P=0.748), and there were high correlations among them(r₁=0.954, r₂=0.973, r₃=0.948). The sample(150 eyes)was divided into 3 groups according to the CCT measurements obtained with ultrasonic pachymetry for further analysis: CCT≤520μm,520μm 570μm. The 3 groups have high relation and good consistency(P>0.05).

CONCLUSION: There are no statistically significant differences among the three instruments, and the correlations of them are high.