J Korean Ophthalmol Soc.  2016 Oct;57(10):1542-1548. 10.3341/jkos.2016.57.10.1542.

Utility of the Swept Source Optical Coherence Tomography for Measurements of Central Corneal Thickness

• Kim IG
• Lee CE
• Lee JS
• Seo S
• Lee KW

• KMID: 2355408
• DOI: http://doi.org/10.3341/jkos.2016.57.10.1542

Abstract

PURPOSE
To evaluate the efficacy of swept source optical coherence tomography (SS-OCT) by comparing the measurement of central corneal thickness (CCT) to the measurement obtained using Orbscan II, anterior segment optical coherence tomography (AS-OCT) and ultrasound pachymetry.
METHODS
One examiner measured the CCT in 65 eyes of 65 healthy subjects using Orbscan II, AS-OCT, SS-OCT and ultrasound pachymetry. The mean values and correlations were analyzed.
RESULTS
The average CCT measurements obtained using Orbscan II, AS-OCT, SS-OCT and ultrasound pachymetry were 534.83 ± 38.46, 517.80 ± 32.48, 528.22 ± 33.71 and 528.02 ± 34.90 µm, respectively. A significant linear correlation was observed among Orbscan II, AS-OCT, SS-OCT and ultrasound pachymetry (r > 0.894, p < 0.001). There was no significant difference between the SS-OCT and ultrasound pachymetry (p = 0.782).
CONCLUSIONS
The results of the 4 methods were significantly correlated and the SS-OCT reached a high level of agreement when CCT was determined using ultrasound pachymetry. The CCT measurements using SS-OCT is a better alternative for ultrasound pachymetry than Orbscan II and AS-OCT.

Keyword

Anterior segment optical coherence tomography; Central corneal thickness; Orbscan II; Swept source optical coherence tomography; Ultrasound pachymetry

MeSH Terms

Healthy Volunteers
Tomography, Optical Coherence*
Ultrasonography

Figure

• 

  Figure 1. Box plots showing mean central corneal thickness measured by Orbscan II, anterior segment optical coherence tomography (AS-OCT), swept source optical coherence tomography (SS-OCT), and ultrasound pachymetry (USP). The horizontal lines within the box represent medians, the ends of the boxes represent the first and third quartiles, and the whiskers represent the smallest and largest non-outlier values.

• 

  Figure 2. The correlation plot of the central corneal thickness (CCT) measured by ultrasound pachymetry (USP), Orbscan II, anterior segment optical coherence tomography (AS-OCT), and swept source optical coherence tomography (SS-OCT). (A) Correlation between USP and Orbscan II (r2 = 0.834, p < 0.001), The best-fit line (y = 0.83× + 83.28) is designated by solid line. (B) Correlation between USP and AS-OCT (r2 = 0.947, p < 0.001), The best-fit line (y = 1.05× −13.48) is designated by solid line.(C) Correlation between USP and SS-OCT (r2 = 0.973, p < 0.001), The best-fit line (y = 1.02× – 11.42) is designated by solid line.(D) Correlation between SS-OCT and Orbscan II (r2 = 0.830, p < 0.001), The best-fit line (y = 0.80× + 99.58) is designated by solid line. (E) Correlation between SS-OCT and AS-OCT (r2 = 0.948, p < 0.001). The best-fit line (y = 1.01× + 4.87) is designated by solid line. (F) Correlation between Orbscan II and AS-OCT (r2 = 0.899, p < 0.001). The best-fit line (y = 1.06× – 14.66) is designated by solid line.

• 

  Figure 3. Bland-Altman plots of the difference in central corneal thickness (CCT, μ m). Bland-Altman plots comparing measurement of CCT (A) between ultrasound pachymetry (USP) and Orbscan II, (B) between USP and anterior segment optical coherence tomography (AS-OCT), (C) between USP and swept source optical coherence tomography (SS-OCT), (D) between SS-OCT and Orbscan II, (E) between SS-OCT and AS-OCT, (F) between Orbscan II and AS-OCT. The middle solid line represents the mean difference in CCT values and the upper and lower dashed lines represent the 95% limits of agreement. SD = standard deviation.

Reference

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