Evaluation and comparison of ocular biometric parameters obtained with Tomey OA-2000 in silicone oil-filled aphakia eyes

Abstract

Purpose To evaluate a new non-contact instrument (OA-2000) measuring the ocular biometry parameters of silicone oil (SO)-filled aphakia eyes, as compared with IOLMaster 700. Methods Forty SO-filled aphakia eyes of 40 patients were enrolled in this cross-sectional clinical trial. The axial length (AL), central corneal thickness (CCT), keratometry (Kf [flattest keratometry] and Ks [steep keratometry, 90° apart from Kf]), and axis of the Kf (Ax1) measured with OA-2000 were compared with those measured with IOLMaster 700. The agreements of the results between the two devices were evaluated by Bland-Altman analysis. The differences of measurement results were evaluated by paired t test, and the correlation was evaluated by the Pearson coefficient. The coefficient of variation (CoV) was calculated to assess the repeatability. Results The mean AL obtained with the OA-2000 was 23.57 ± 0.93mm (range: 21.50 to 25.68mm), and that obtained with the IOLMaster 700 was 23.69 ± 0.94mm (range: 21.85 to 25.86mm), resulting in a mean offset of 0.124 ± 0.125mm (p < 0.001). The mean offset of CCT measured by OA-2000 and IOLMaster 700 was 14.6 ± 7.5µm (p < 0.001). However, the Kf, Ks and Ax1 values from the two devices were comparable (p > 0.05). All the measured parameters of the two devices showed strong linear correlations (all r ≥ 0.966). Bland-Altman analysis showed a narrow 95% limits of agreement (LoA) of Kf, Ks and AL, but 95%LoA of CCT and Ax1 was wide, which were − 29.3 ~ 0.1µm and-25.9 ~ 30.7°respectively. The CoVs of the biometric parameters obtained with OA-2000 were lower than 1%. Conclusion In SO-filled aphakia eyes, the ocular parameters (including AL, Kf, Ks, Ax1, and CCT) measured by the OA-2000 and IOLMaster 700 had a good correlation. Two devices had an excellent agreement on ocular biometric measurements of Kf, Ks and AL. OA-2000 provided excellent repeatability of ocular biometry parameters in SO-filled aphakia eyes.