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Oh, Cho, Moon, and Kim: Repeatability and Agreement of Macular Thickness Measurement Using Time Domain OCT and Spectral Domain OCT in Normal Subjects
Original Article

J Korean Ophthalmol Soc 2009;50(5):710-716.

Published online: 7 September 2009

DOI: https://doi.org/10.3341/jkos.2009.50.5.710

Repeatability and Agreement of Macular Thickness Measurement Using Time Domain OCT and Spectral Domain OCT in Normal Subjects

Se Beum Oh, MD, Won Bin Cho, MD, Jun Woong Moon, MD, Hyung Chan Kim, MD

Department of Ophthalmology, College of Medicine, Konkuk University, Seoul, Korea

Address reprint requests to Hyung Chan Kim, MD Department of Ophthalmology, Konkuk University Medical Center, Konkuk University School of Medicine #4-12 Hwayang-dong, Gwangjin-gu, Seoul 143-729, Korea Tel: 82-2-2030-5270, Fax: 82-2-2030-5273, E-mail: eyekim@kuh.ac.kr

Received 10 October 2008       Accepted 14 January 2009

Copyright © 2009 Korean Ophthalmological Society

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 compare the repeatability and agreement of macular thickness measurements using time domain (TD) optical coherence tomography (OCT) and spectral domain (SD) OCT in normal subjects.

Methods

Thirty-four normal subjects were included. Three consecutive macular measurements were taken with TD OCT and SD OCT. Total and regional macular thickness and total macular volume obtained by the two OCTs were compared. Within-subject standard deviation (Sw), coefficient of variation (CVw), and the intraclass correlation coefficient (ICC) were calculated to evaluate repeatability. The agreement was examined with Bland Altman plots. The correlation was also evaluated with Pearson correlation coefficients and multiple regression analysis.

Results

Sw for foveal thickness, total macular thickness, and total macular volume were 11.53 μ m, 7.58 μ m, and 0.48 mm3 for TD OCT and 6.69 μ m, 2.55 μ m, and 0.09 mm3 for SD OCT, respectively. The values for SD OCT were consistently lower, and this result was statistically significant. The range of the respective CVw and ICC values were 1.10∼2.78% and 0.78∼0.96% for TD OCT, and 0.29∼0.94% and 0.92∼0.99% for SD OCT, respectively. The SD OCT showed better repeatability for macular thickness measurements(all with p≤0.001). The spans of 95% limits of agreement for foveal thickness, total macular thickness, and total macular volume were 67.94 μ m, 29.01 μ m, and 0.98 mm3, respectively. The Pearson correlation coefficient of foveal thickness, total macular thickness, and total macular volume between the two OCT's was statistically significant.

Conclusions

Although both OCTs are reliable for macular thickness measurements, SD OCT shows better repeatability compared with TD OCT. Although macular thickness measurements obtained from the two OCTs can not be used interchangeably due to low agreement by different standards of measurement, there was a statistically significant correlation between the two OCT's.

Keywords: Coefficient of variation, Intraclass correlation coefficient, Spectral domain OCT, Time domain OCT, Within-subject standard deviation

References

1. Zeimer RC, Mori MT, Khoobehi B. Feasibility test of a new method to measure retinal thickness noninvasively. Invest Ophthalmol Vis Sci. 1989; 30:2099–105.
2. Gieser JP, Rusin MM, Mori M, et al. Clinical assessment of the macular by retinal topography and thickness mapping. Am J Ophthalmol. 1997; 124:648–60.
3. Polito A, Shah SM, Haller JA, et al. Comparision between retinal thickness analyzer and optical coherence tomography for assessment of foveal thickness in eyes with macular disease. Am J Ophthalmol. 2002; 134:240–51.
4. Puliafito CA, Hee MR, Schuman JS, et al. Optical coherence tomography of ocular disease. Thorofare, NJ: Slack;1996. p. 369–74.
5. Muscat S, Parks S, Kemp E, et al. Repeatability and reproducibility of macular thickness measurements with the Humphrey system. Invest Ophthalmol Vis Sci. 2002; 43:490–5.
6. Hangai M, Ojima Y, Gotoh N, et al. Three-dimensional imaging of macular holes with high-speed optical coherence tomography. Ophthalmology. 2007; 114:763–73.
crossref
7. Ahlers C, Michels S, Beckendorf A, et al. Three-dimensional imaging of pigment epithelial detachment in age-related macular degeneration using optical coherence tomography, retinal thickness analysis and topographic angiography. Graefes Arch Clin Exp Ophthalmol. 2006; 244:1233–9.
crossref
8. Bland JM, Altman DG. Statistical methods for assessing agreement between two methods of clinical measurement. Lancet. 1986; 1:307–10.
crossref
9. Bland JM. Comparing within-subject variance in a study to compare two methods of measurement. Available at. http://www-users.york.ac.uk~/mb55/meas/compsd.pdf.
10. Massin P, Vicaut E, Haouchine B, et al. Reproducibility of retinal mapping using optical coherence tomography. Arch Ophthalmol. 2001; 119:1135–42.
crossref
11. Shrout PE, Fleiss JL. Intraclass correlations: uses in assessing rater reliability. Pshychol Bull. 1979; 428–9.
crossref
12. Gurses-Ozden R, Teng C, Vessani R, et al. Macular and retinal nerve fiber layer thickness measurement reproducibility using optical coherence tomography (OCT-3). J Glaucoma. 2004; 13:238–44.
13. Paunescu LA, Schuman JS, Price LL, et al. Reproducibility of nerve fiber thickness, macular thickness, and optic nerve head measurements using Stratus OCT. Invest Ophthalmol Vis Sci. 2004; 45:1716–24.
14. Yoon SC, Lee DY, Nam DH. Macular thickness in healthy Korean eyes using OCT3 comparing with normative data. J Korean Ophthalmol Soc. 2008; 49:601–10.
crossref
15. Hendrickson A, Drucker D. The development of parafoveal and mid-peripheral human retina. Behav Brain Res. 1992; 49:21–31.
crossref
16. Spraul CW, Lang GE, Grossniklaus HE. Morphometric analysis of the choroid, Bruch's membrane, and retinal pigment epithelium in eyes with age-related macular degeneration. Invest Ophthalmol Vis Sci. 1997; 38:1290–2.

Figure 1.
Bland‐Altman plots of foveal thickness measurements obtained by Stratus OCT and Spectralis OCT. Solid line indicates the average mean difference, while dotted lines delineates the 95% confidence limits of agreement.
jkos-50-710f1.tif
Figure 2.
Bland‐Altman plots of total macular thickness obtained by Stratus OCT and Spectralis OCT. Solid line indicates the average mean difference, while dotted lines delineates the 95% confidence limits of agreement.
jkos-50-710f2.tif
Figure 3.
Bland‐Altman plots of total macular volume obtained by Stratus OCT and Spectralis OCT. Solid line indicates the average mean difference, while dotted lines delineates the 95% confidence limits of agreement.
jkos-50-710f3.tif
Table 1.
Comparison of regional and total macular thicknesses measured by spectral domain and time domain optical coherence tomography
Stratus OCT (mean±SD) Spectralis OCT (mean±SD) p values mean difference (SD OCT–TD OCT) 95% limits of Agreement
Foveal thickness 198.4±24.4 262.4±17.6 <0.001 64.0 67.94 (30.02–97.96)
Temporal inner thickness 276.8±17.7 339.0±14.4 <0.001 62.2 39.97 (42.18–82.15)
Superior inner thickness 273.2±19.3 336.9±14.4 <0.001 63.7 55.11 (36.11–901.22)
Nasal inner thickness 277.2±18.3 339.0±14.4 <0.001 61.8 39.77 (41.89–81.66)
Inferior inner thickness 270.9±14.9 335.1±13.1 <0.001 64.2 32.59 (47.93–80.52)
Temporal outer thickness 223.3±14.9 282.4±12.3 <0.001 59.1 33.85 (42.18–76.03)
Superior outer thickness 242.7±16.0 310.2±12.5 <0.001 57.6 45.53 (34.80–80.33)
Nasal outer thickness 260.8±23.7 320.8±15.0 <0.001 59.9 76.24 (21.80–98.04)
Inferior outer thickness 227.5±16.4 286.7±12.3 <0.001 59.3 39.13 (39.70–78.83)
Total macular thickness 252.3±4.5 312.3±2.9 <0.001 60.0 29.01 (45.48–74.49)
Total macular volume 6.8±0.4 8.7±0.4 <0.001 1.93 0.98 (1.44–2.42)
Table 2.
Within–subject standard deviation (Sw), coefficient of variation (CVw), and intraclass correlation coefficient (ICC) of total and regional macular thicknesses obtained with time domain OCT and spectral domain OCT
Foveal thickness Temporal Inner Thickness Superior Inner Thickness Nasal Inner Thickness Inferior Inner Thickness Temporal Outer Thickness Superior Outer Thickness Nasal Outer Thickness Inferior Outer Thickness T Total macular Thickness Total volume
Sw TD OCT 11.53 14.55 21.06 17.03 15.82 12.94 14.05 16.09 12.89 7.58 0.48
SD OCT 6.69 7.54 3.81 7.54 3.69 7.47 5.07 6.96 7.73 2.55 0.09
CVw TD OCT 2.13 1.92 2.78 2.25 2.12 2.16 2.13 2.23 2.05 1.10 2.53
SD OCT 0.90 0.78 0.40 0.78 0.39 0.94 0.60 0.78 0.97 0.29 0.36
ICC TD OCT 0.957 0.871 0.777 0.839 0.788 0.854 0.851 0.910 0.879 0.942 0.703
SD COT 0.976 0.947 0.986 0.947 0.985 0.930 0.969 0.961 0.923 0.991 0.992
p values* <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

* Comparison of within–subject variances between Stratus OCT and Spectralis OCT (paired t test on log–transformed data).

Table 3.
Pearson correlation coefficient of macular thicknesses and total macular volume obtained with time domain OCT and spectral domain OCT
Fovealt thickness Temporal Inner Thickness Superior Inner Thickness Nasal Inner Thickness Inferior Inner Thickness Temporal Outer Thickness Superior Outer Thickness Nasal Outer Thickness Inferior Outer Thickness Total macular Thickness Total volume
Pearson correlation coefficient 0.686 0.752 0.595 0.752 0.742 0.739 0.629 0.536 0.725 0.820 0.708
p values* <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001 <0.001

* Pearson's correlation coefficient between Stratus OCT and Spectralis OCT.

Table 4.
Multiple regression analysis between time domain OCT and spectral domain OCT
Spectralis OCT (dependent variable) A (TD–OCT)(TD–OCT)+B (TD–OCT)+C (independent variable) p values
A B C
Foveal thickness –0.005 (TD–COT)(TD–OCT)+2.486 (TD–OCT)-23.732 <0.001 <0.001 0.612
Temporal inner thickness 0.004 (TD–OCT)(TD–OCT)-1.551 (TD–OCT)+475.933 0.006 0.048 <0.001
Superior inner thickness 0.007 (TD–OCT)(TD–OCT)-3.140 (TD–OCT)+695.931 <0.001 <0.001 <0.001
Nasal inner thickness 0.003 (TD–OCT)(TD–OCT)-1.186 (TD–OCT)+430.137 0.020 0.120 <0.001
Inferior inner thickness 0.018 (TD–OCT)(TD–OCT)-9.138 (TD–OCT) +1471.195 <0.001 <0.001 <0.001
Temporal outer thickness 0.010 (TD–OCT)(TD–OCT)-3.532 (TD–OCT)+590.398 <0.001 <0.001 <0.001
Superior outer thickness 0.007 (TD–OCT)(TD–OCT)-2.684 (TD–OCT)+567.373 0.002 0.007 <0.001
Nasal outer thickness –0.004 (TD–OCT)(TD–OCT)+2.725 (TD–OCT)-99.631 <0.001 <0.001 0.203
Inferior outer thickness –0.009 (TD–OCT)(TD–OCT)+4.720 (TD–OCT)-316.367 <0.001 <0.001 0.001
Total macular thickness 0.005 (TD–OCT)(TD–OCT)-1.903 (TD–OCT)+463.957 0.028 0.108 0.002
Total macular volume 0.393 (TD–OCT)(TD–OCT)-4.546 (TD–OCT)+21.3 <0.001 0.001 <0.001
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