AIM: To investigate the differences among Lenstar 900, A-scan ultrasound and keratometer in measurement of axial length(AL), anterior chamber depth(ACD)and corneal curvature(K₁, K₂, Km), and evaluate the consistency of the instruments, with the purpose providing references for the clinical application of Lenstar 900.

METHODS: In this study we picked up 36 patients(50 eyes)underwent cataract surgery, and lens nucleus hardness were under level IV. Before the operation, AL, ACD and K₁ , K₂, Km were measured by Lenstar 900, A-scan ultrasound and keratometer respectively. The differences between the results were compared by the paired t-test. The correlation of the results was analyzed by Pearson correlation analysis, and the consistency was measured by Bland-Ahamn method.

RESULTS: The mean AL and ACD values measured by Lenstar 900 and A-scan ultrasound had no significantly statistic differences(P>0.05). The K₁ , K₂, Km measured by Lenstar 900 and keratometer were not significantly statistical different(P>0.05). The results measured by these three instruments had close linearity correlation(r>0.9, P<0.01). The consistency of the results was well in Bland-Ahamn analysis.

CONCLUSION:The preoperatively biometric result of Lenstar 900, A-scan ultrasound and keratometer in patients with cataract are all reliable, and they can be substituted by each other. However, Lenstar 900 can not only measure AL, ACD and corneal curvature at the same time, but also cornal thickness, lens thickness, white to white, pupil size, optical axis eccentricity, retinal thickness and so on. It has a number of advantages such as non-touching, convenient and efficient, and can be recommended to use widely.