Reproducibility and Agreement of Anterior Segment Parameter Measurements Obtained Using the CASIA2 and Spectralis OCT2 Optical Coherence Tomography Devices

Abstract

Purpose

To assess the reproducibility and agreement of measurement values obtained from the Tomey CASIA2 and Heidelberg Spectralis OCT2 anterior segment optical coherence tomography (AS-OCT) devices.

Methods

Twenty eyes from ten subjects ranging from age 28 to 45 years with no history of eye conditions or intraocular surgery were included. Two scans were obtained with each device in a standardized dark-room environment after a period of dark adaptation. One AS-OCT image along the horizontal (temporal-nasal) meridian was analyzed per eye and per scan. Lens vault (LV), pupil diameter (PD), anterior chamber width (ACW), angle opening distance (AOD), trabecular iris space area (TISA), and scleral spur angle (SSAngle) were measured using manufacturer-provided image analysis programs. Intra-class correlation (ICC) values, coefficients of variation, and Bland-Altman plots were computed to assess the intra-device correlation and inter-device agreement of measurement values.

Results

There was excellent intra-device reproducibility of measurement values for both the CASIA (ICC range 0.86 to 0.99) and Spectralis (ICC range 0.79 to 1.00). There was also excellent inter-device correlation of measurement values (ICC range 0.78 to 0.93) for all parameters except ACW (ICC 0.20). Linear regression models and Bland-Altman plots showed that this relationship was strongest when measurement values were small.

Conclusion

There is excellent intra-device reproducibility and good inter-device agreement of anterior segment parameter measurement values for the CASIA2 and Spectralis OCT2. However, the measurements obtained with each device should not be considered interchangeable.