Evaluation of the Lenstar LS 900 non-contact biometer

Background/aims: Evaluation of the reproducibility of the Lenstar LS 900 non-contact biometer, and a comparison with the Visante anterior-segment optical coherence tomography (AS-OCT) and the IOLMaster.

Methods: Central corneal thickness (CCT), anterior chamber depth (ACD), lens thickness (LT), keratometry (K) values, corneal diameter (CD) and axial length (AL) were obtained in 38 healthy volunteers (76 eyes) to determine the reproducibility of the Lenstar. CCT, ACD, CD, K values and AL measurements measured with the Lenstar were compared with the AS-OCT and IOLMaster. Intraocular lens (IOL) power calculations were done to study the significance of the difference between AL measurements.

Results: The reproducibility of the Lenstar was better than 0.9% for CCT, ACD, LT, K values and AL measurements. Although all correlations were highly significant (p <0.001), all comparisons showed a significant difference, except for the comparison of CD measurements using the Lenstar and IOLMaster (p = 0.175). The differences in IOL power calculations for an AL of 20, 25 and 30 mm with a mean difference between Lenstar and IOLMaster AL measurements of 0.03 mm, were 0.13 D, 0.10 D and 0.08 D, respectively.

Conclusion: The reproducibility of the Lenstar was excellent. Small but significant differences exist between the Lenstar, Visante OCT and the IOLMaster. Therefore, measurements of the Lenstar, AS-OCT and IOLMaster are not interchangeable. Despite the significant difference between AL measurements, there is no clinically significant difference in the IOL power calculation results.