Comparison of the new biometer OA-1000 with IOLMaster and Tomey AL-3000

The OA-1000 (Tomey, Japan) is a new optical biometer, which allows measurements of axial length (AL), anterior chamber depth (ACD) and corneal thickness (CT) due to partial coherence interferometry (PCI) technology. The aim of this study was to compare the OA-1000 results with those obtained with the IOLMaster and contact applanation A-scan ultrasonography.

We examined 133 eyes of 75 patients with age related cataract. Mean age was 72.0 ± 9.5 years. Biometry measurements of AL and ACD were performed with the Tomey OA-1000 based on PCI, the IOLMaster based on PCI (AL) and slit projection (ACD), and the Tomey AL-3000 based on contact applanation A-scan ultrasonography.

Mean AL using the IOLMaster was 23.21 ± 1.08 mm, using the AL-3000 was 22.79 ± 1.04 mm, using the OA-1000 it was 22.97 ± 1.1 mm. Mean ACD using the IOLMaster was 2.99 ± 0.41 mm, using the OA-1000 3.40 ± 0.46 mm, using the Tomey AL-3000 it was 2.93 ± 0.43 mm. Mean difference between the AL and ACD measured with the OA-1000 and the IOLMaster was 0.22 ± 0.047 mm and 0.40 ± 0.33 mm, between OA-1000 and the AL-3000 it was 0.19 ± 0.23 mm and 0.47 ± 0.33 mm, and between IOLMaster and AL-3000 it was 0.42 ± 0.23 and 0.09 ± 0.36 mm. For AL the correlation coefficient R between IOLMaster and OA-1000 was 0.999, between IOLMaster and AL-3000 it was 0.976, between AL-3000 and OA-1000 it was 0.977. For ACD R between IOLMaster and OA-1000 was 0.735, between IOLMaster and AL-3000 it was 0.822, between AL-3000 and OA-1000 it was 0.716 (all p < 0.001).

Compared with other used clinical instruments the OA-1000 generates accurate results. Although differences were found, the OA-1000 provided results that correlated well with the values of IOLMaster and AL-3000.