Comparison of Anterior Segment Parameters Obtained by Anterior Segment Optical Coherence Tomography and Dual Rotating Scheimpflug Camera

ABSTRACT

PURPOSE: To compare the anterior segment measurements with a Galilei® dual Scheimpflug analyzer and anterior segment optical coherence tomography (Cirrus OCT®). METHODS: Forty-eight eyes of 24 normal young adults were assessed for repeatability with two identical measurements of the central corneal thickness, minimum corneal thickness, anterior chamber depth, and anterior chamber angle using the Galilei® dual-Scheimpflug analyzer and Cirrus OCT®. RESULTS: The central corneal thickness, anterior chamber depth, and anterior chamber angle were highly reproducible and repeatable (intraclass correlation coefficient ≥ 0.90). Repeatability of the minimum corneal thickness was slightly lower (intraclass correlation coefficient ≥ 0.69). The mean corneal thickness measured using the Galilei® dual Scheimpflug analyzer was 0.26 ± 7.11 µm thinner than that measured using the Cirrus OCT®, and the mean corneal thickness was 0.37 ± 7.35 µm thicker, but was not statistically significant. The anterior chamber depth was 0.22 ± 0.08 mm deeper than the Cirrus OCT® (p < 0.007), and the anterior chamber angle was 7.87°± 1.32° larger than the Cirrus OCT® (p = 0.04). The 95% agreements of the central corneal thickness, anterior chamber depth, and anterior chamber angle between instruments were 85.30 µm, 1.43 mm, and 27.90°, respectively, and showed a high correlation (r ≥ 0.90; p < 0.001). The repeatability of the minimum corneal thickness was slightly low (r = 0.69; p < 0.001), and the range of agreement was larger (109.58 µm). CONCLUSIONS: The anterior segment measurements obtained with the dual rotating Scheimpflug camera and new anterior segment OCT in normal eyes was comparable and reproducible. However, the agreement ranges of the measured values were relatively large, so it was difficult to exchange values between instruments.