J Korean Ophthalmol Soc.  2017 Dec;58(12):1341-1348. 10.3341/jkos.2017.58.12.1341.

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

• Ha DY
• Jung JW

• KMID: 2397848
• DOI: http://doi.org/10.3341/jkos.2017.58.12.1341

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.

Keyword

Anterior chamber angle; Anterior chamber depth; Anterior segment optical coherence tomography; Corneal thickness; Dual Scheimpflug analyzer

MeSH Terms

Anterior Chamber
Humans
Tomography, Optical Coherence*
Young Adult

Figure

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  Figure 1 An example of the pachymetry mode of the Cirrus OCT®. Every sector has three values, which indicates the minimum, average, and maximum corneal thicknesses. The average value is representative of each sector.

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  Figure 2 The angle opening distance 500 was measured on a line perpendicular to the trabecular meshwork at points 500 µm from the scleral spur. The anterior chamber angle (ACA) was measured on this image (white dotted line). AOD = angle opening distance.

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  Figure 3 Bland Altman plots between the parameters of the two instruments. The middle line is the mean and the lines on the side represent the upper and lower 95% limits of agreement. (A) The average central corneal thickness using the Galilei® dual Scheimpflug analyzer and Cirrus OCT®. (B) The average minimum corneal thickness using the Galilei® dual Scheimpflug analyzer and Cirrus OCT®. (C) The average anterior chamber depth using the Galilei® dual-Scheimpflug analyzer and Cirrus OCT®. (D) The average anterior chamber angle using the Galilei® dual Scheimpflug analyzer and Cirrus OCT®. CCT = central corneal thickness; MCT = minimum corneal thickness; ACD = anterior chamber depth; ACA = anterior chamber angle.

• 

  Figure 4 Scattergram showing correlations of the anterior chamber depth, central corneal thickness, minimum corneal thickness, and anterior chamber angle using the Galilei® dual Scheimpflug analyzer and Cirrus OCT®. (A) The correlation of central corneal thicknesses between the Galilei® dual Scheimpflug analyzer and Cirrus OCT® (r = 0.99; p < 0.01). (B) The correlation of the minimum corneal thickness between the Galilei® dual Scheimpflug analyzer and Cirrus OCT® (r = 0.69; p < 0.01). (C) The correlation of the anterior chamber depth between the Galilei® dual Scheimpflug analyzer and Cirrus OCT® (r = 0.90; p < 0.01). (D) The correlation of the anterior chamber angle between the Galilei® dual Scheimpflug analyzer and Cirrus OCT® (r = 0.92; p < 0.01). CCT = central corneal thickness; MCT = minimum corneal thickness; ACD = anterior chamber depth; ACA = anterior chamber angle.

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