Utility of the Anterior Segment Optical Coherence Tomography for Measurements of Central Corneal Thickness

Hyoung Sub Shim; Chul Young Choi; Hee Gyung Lee; Myoung Joon Kim; Hung Won Tchah

doi:10.3341/jkos.2007.48.12.1643

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Shim, Choi, Lee, Kim, and Tchah: Utility of the Anterior Segment Optical Coherence Tomography for Measurements of Central Corneal Thickness

Original Article

J Korean Ophthalmol Soc 2007;48(12):1643-1648.

Published online: 30 August 2007

DOI: https://doi.org/10.3341/jkos.2007.48.12.1643

Utility of the Anterior Segment Optical Coherence Tomography for Measurements of Central Corneal Thickness

Hyoung Sub Shim, M.D.¹, Chul Young Choi, M.D.¹, Hee Gyung Lee, M.D.², Myoung Joon Kim, M.D², Hung Won Tchah, M.D²

¹Department of Ophthalmology, Gangbuk Samsung Hospital, Sungkyunkwan University School of Medicine, Seoul, Korea

²Department of Ophthalmology, University of Ulsan College of Medicine, Asan Medical Center, Seoul, Korea

Address reprint requests to Chul Young Choi, M.D., Department of Ophthalmology, Gangbuk Samsung Hospital, College of Medicine, Sungkyunkwan University, #108 Pyung-dong, Jongro-gu, Seoul 110-746, Korea Tel: 82-2-2001-2250, Fax: 82-2-2001-2262, E-mail: sashimi0@naver.com

Received 23 April 2007 Accepted 31 July 2007

This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0/) which permits unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Purpose

To demonstrate the capability of anterior segment optical coherence tomography (OCT), to evaluate central corneal thickness (CCT) and to compare the results with those by Orbscan II and standard ultrasound (US) pachymetry.

Methods

One examiner measured the CCT of 44 normal eyes of 22 subjects using anterior OCT, Orbscan II, and US pachymetry. Non-contact measurements by anterior segment OCT and Orbscan II were performed first, followed by contact measurements using US pachymehy. Three consecutive measurements were taken with each method and the mean values and correlations were analyzed.

Results

The mean value of the CCT was 531.45±32.90 μm with anterior OCT, 537.11±32.21 pm with Orbscan II, and 548.18±34.17 pm with US pachymehy. There was no statistically significant difference among the values obtained by the 3 instruments (P>0.05). CCT measurements by anterior segment OCT were highly correlated with Orbscan II and US pachymetry (P<0.001) measurements.

Conclusion

CCT measurements by anterior segment OCT are highly correlated with Orbscan II or US pachymetry measurements. Using non-contact anterior segment OCT, a closer examination of the anterior segment including the cornea is possible. The measurement of the CCT using anterior segment OCT is applicable because result values are similar to measurements by Orbscan II or US pachymetry.

Keywords: Central corneal thickness, Orbscan, Optical coherence tomography, Ultrasound pachymetry

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Figure 1.

Data were obtained from central 2 mm zone in OCT pachymetry map.

Figure 2.

Scatterplot showing correlation between ultrasound pachymetry (Ultra) and OCT measurements of central corneal thickness in individuals (Pearson's correlation coefficient r = 0.981, P<0.001).

Figure 3.

Scatterplot showing correlation between Orbscan II (ORB) and OCT measurements of central corneal thickness in individuals (Pearson's correlation coefficient r = 0.976 P<0.001).

Table 1.

Summary of CCT measurements

CCT^*	Anterior OCT	Orbscan II	US^† pachymeter
Mean CCT + SD (μm)	531.45±32.90	537.11±32.21^‡	548.18±34.17
CCT Range (μm)	479-585	480-585^‡	492-604

^* CCT=central corneal thickness;

^† US=ultrasound.

^‡ Corrected Orbscan value=raw Orbscan value × 0.92 of acoustic correction factor as proposed by the manufacturer.

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