Repeatability and interobserver reproducibility of a new optical biometer based on swept-source optical coherence tomography and comparison with IOLMaster.

Abstract

To evaluate the precision of the measurements in healthy subjects obtained with a new optical biometer (OA-2000, Tomey, Nagoya, Japan) using swept-source optical coherence tomography (SS-OCT) and compare these measurements with those provided by the IOLMaster v5.4 (Carl Zeiss Meditec AG, Jena, Germany) using partial coherence interferometry (PCI). Axial length (AL), keratometry (K) over 2.5 mm and 3.0 mm diameters, anterior chamber depth (ACD) (corneal epithelium to lens), lens thickness (LT), central corneal thickness and corneal diameter (CD) were measured with SS-OCT by two experienced operators. Intraobserver repeatability and interobserver reproducibility were assessed. AL, ACD, K and CD were also measured with PCI for agreement analysis using Bland-Altman plots. Sixty-five eyes of 65 normal subjects were enrolled in the prospective study. The SS-OCT measurements revealed high repeatability and reproducibility with low test-retest repeatability, low within-subject coefficient of variation (CoV) and high intraclass correlation coefficients. Bland-Altman analysis showed narrow 95% limits of agreement for most parameters indicating excellent agreement for AL (-0.05 mm to 0.07 mm), K values both at 2.5 mm (-0.42 D to 0.20 D) and 3.0 mm (-0.42 D to 0.08 D) and ACD (-0.19 mm to 0.22 mm) except for the CD (-1.11 mm to -0.01 mm). The repeatability and reproducibility of SS-OCT were excellent for all parameters including AL, K, ACD, LT and CD values. High agreement was shown between SS-OCT and PCI for most biometrical parameters.