Spectral-domain Optical Coherence Tomography Retinal and Choroidal Thickness Metric Repeatability in Age-related Macular Degeneration

doi:10.1016/j.ajo.2016.03.052

American Journal of Ophthalmology

Volume 166, June 2016, Pages 154-161

https://doi.org/10.1016/j.ajo.2016.03.052 Get rights and content

Purpose

To determine the intrasession repeatability of spectral-domain OCT (SDOCT)-derived macular retinal and choroidal metrics in patients with neovascular age-related macular degeneration (nAMD) in the Distance of Choroid Study (DOCS).

Design

Validity and reliability analysis.

Methods

Enrolled patients underwent repeated SDOCT imaging using the Spectralis OCT (Heidelberg Engineering, Heidelberg, Germany). A single technician certified for clinical trials took 3 macular volume scans. Retinal thicknesses were calculated for each of the 9 Early Treatment Diabetic Retinopathy Study (ETDRS) macular subfields. Center point thickness and total macular volume were also included in the analysis. Manual subfoveal choroidal thickness measurements were made by a masked observer.

Results

A total of 40 eyes of 40 patients were included in this analysis (mean [± standard deviation] age: 74.1 [± 7.2] years, 60% male). The coefficient of repeatability (CR) of the central macular subfield was 30.6 μm (95% confidence interval [CI] 29.8–1.4 μm). The CR for the other macular subfields ranged from 7.0 μm to 38.2 μm. The CR for the total macular volume was 0.212 mm³ (95% CI 0.206–0.217 mm³) and the CR for the center point was 47.5 μm (95% CI 46.2–48.7 μm). Images were also reviewed for the presence of segmentation error in the central macular subfield, and after exclusion of these eyes the revised CR for this subfield was 13.7 μm (95% CI 13.3–14.1 μm). The intrasession CR of subfoveal choroidal thickness was 34.7 μm (95% CI 33.7–35.7 μm).

Conclusions

This study suggests that a change of greater than 31 μm in Spectralis SDOCT–derived retinal thickness measurement of the central macular subfield and 35 μm in subfoveal choroidal thickness is necessary to detect true clinical change associated with disease progression or improvement in nAMD with a revised figure of 14 μm for central macular retinal subfield thickness in the absence of segmentation error.

Section snippets

Methods

This study analysis formed part of the Distance of Choroid Study (DOCS). This was a prospective cross-sectional study assessing the repeatability of thickness measurements of the posterior coat of the eye (sclera, choroid, and retina) in eyes with nAMD using a range of imaging modalities. All subjects provided informed written consent prior to study inclusion. The study was approved by the local research ethics committee (NRES Committee South East Coast–Surrey) and adhered to the tenets set

Patient Characteristics

Forty patients were included in the analyses (Table 1). All images were acquired between February 4, 2014 and July 7, 2014. The mean age (± SD) of the patients was 74.1 (± 7.2) years. There were 24 male and 16 female subjects. Eighteen left eyes and 22 right eyes were included in the study. The mean BCVA (± SD) was 64.4 (± 18.6) ETDRS letters. Thirty-eight of the 40 subjects (95%) had undergone treatment with intravitreous antiangiogenic agents in the previous 6 months.

Retinal and Choroidal Thickness Measurements

The mean (± SD) automated

Discussion

SDOCT-derived macular thickness and volume data are used in both clinical practice and research domains to identify macular disease progression or improvement, to determine the efficacy of macular treatments, to guide further treatment, and as an endpoint in clinical trials.23, 24, 25, 26 It is imperative, therefore, to understand the repeatability of SDOCT-derived macular thickness variables in patients with nAMD in order to distinguish true clinical change from measurement variability.

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Cited by (14)

Repeatability and reproducibility of manual choroidal thickness measurement using Lenstar images in children before and after orthokeratology treatment
2022, Contact Lens and Anterior Eye
Citation Excerpt :
However, it is not known whether this association persists over a longer period of time. Before the development of analyzing software, choroidal thickness, acquired by OCT, was determined manually and the coefficient of repeatability of intra-session repeatability varied from 35 to 54 µm [34–37]. Later, with the help of an automatic segmentation technique, which facilitated the determination of chorio-scleral interface, automatic segmentation of the choroidal layer was established.
To investigate the repeatability and reproducibility of choroidal thickness measurements using Lenstar images in young myopic children before and after one-month orthokeratology (ortho-k) treatment.
Ocular biometry of 39 subjects were performed using the Lenstar 900. The first five measurements with maximum differences of 0.02 mm in axial length in the right eyes were saved and used for measurement of choroidal thickness. Subfoveal choroidal thickness were manually measured by identifying the signals from the retinal pigmented epithelium layer and chorioscleral interface. Repeatability was determined by comparing measurements of the same images made by the same observer on two separate occasions (four weeks apart), while reproducibility was calculated by comparing measurements of the same images made by two independent observers. Data was analysed using intra-class correlation coefficients (ICC) and non-parametric Bland and Altman plots.
The choroidal peaks could not be identified in all five measurements in all subjects. On average, only 71% subjects had at least four definable images. Compared with the use of fewer than four images, reliability using an average of four definable images improved statistically, but remained clinically unacceptable (>10 µm), although pre- and post-ortho-k ICC values were good to excellent for repeatability (0.867 and 0.975, respectively) and excellent and good for reproducibility (0.959 and 0.868, respectively). Non-parametric pre- and post-ortho-k limits of agreement (2.5% and 97.5% percentiles) obtained were −45.8 to 79.3 µm and −30.3 to 9.5 µm, respectively for repeatability, and −29.0 to 33.5 µm and −21.8 to 70.0 µm, respectively for reproducibility.
Choroidal thickness measurements using the Lenstar did not show good reliability, despite the high ICC values, non-parametric Bland and Altman plots demonstrated a wide variability of measurement errors. Any changes in subfoveal choroidal thickness, measured by Lenstar, of <80 µm may not represent real changes.
Macular Fluid Reduces Reproducibility of Choroidal Thickness Measurements on Enhanced Depth Optical Coherence Tomography
2017, American Journal of Ophthalmology
Citation Excerpt :
We hypothesize that the accuracy of CT measurements is more dependent on anatomic factors that may affect light penetration and signal strength at the posterior boundary of the choroid than on the biological process underlying the retinal exudation. Prior reports in eyes with neovascular AMD demonstrated intergrader CR values of 30-36 μm, which were comparable to other reports from normal eyes15,22,26 but lower compared to our prior study. Those results may have been confounded by eyes with a thinner choroid, which tends to occur in advanced AMD.
To determine if different types of retinal fluid in the central macula affect the reproducibility of choroidal thickness (CT) measurements on enhanced depth imaging optical coherence tomography (EDI-OCT).
Retrospective reliability analysis.
EDI-OCT images were obtained and the choroidal-scleral junction was analyzed through semiautomated segmentation. CT was measured at the fovea and averaged across the central 3-mm horizontal segment. Demographic data, central macular thickness, and type of fluid present were recorded. Intragrader and intergrader repeatability were assessed using the intraclass correlation coefficient (ICC) and coefficient of repeatability (CR).
Of 124 eyes analyzed, 60 (48.4%) had diabetic macular edema, 32 (25.8%) had neovascular age-related macular degeneration, and 32 (25.8%) had other causes of fluid. Intergrader ICC (CR) was 0.95 (74.1 μm) and 0.96 (63.9 μm) for subfoveal and average CT, respectively. CR was similar across various causes of retinal fluid, but was worst for subretinal fluid compared to intraretinal or sub–retinal pigment epithelial fluid. CR also worsened with increasing choroidal thickness, but was not affected by retinal thickness. Intragrader repeatability was generally greater than intergrader values, and followed the same trend.
The presence of macular fluid reduces CT measurement reproducibility, particularly in eyes with subretinal fluid and greater choroidal thickness. A difference of 74.1 μm in subfoveal CT or 63.9 μm in average CT may be necessary to detect true clinical change in eyes with macular fluid.
Reply
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Measurement of Foveal Retinal Thickness in Myopic Patients Using Different Display Modes on Optical Coherence Tomography: A Retrospective, Cross-Sectional Study
2023, Ophthalmology and Therapy
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Original articleSpectral-domain Optical Coherence Tomography Retinal and Choroidal Thickness Metric Repeatability in Age-related Macular Degeneration

Purpose

Design

Methods

Results

Conclusions

Section snippets

Methods

Patient Characteristics

Retinal and Choroidal Thickness Measurements

Discussion

Ophthalmic imaging by spectral optical coherence tomography

Am J Ophthalmol

Optical coherence tomography

Science

Evaluation of optical coherence tomography retinal thickness parameters for use in clinical trials for neovascular age-related macular degeneration

Invest Ophthalmol Vis Sci

Improved signal-to-noise ratio in spectral-domain compared with time-domain optical coherence tomography

Opt Lett

A review of algorithms for segmentation of optical coherence tomography from retina

J Med Signals Sens

Enhanced depth imaging spectral-domain optical coherence tomography

Am J Ophthalmol

Relationship between visual acuity and spectral domain optical coherence tomography retinal parameters in neovascular age-related macular degeneration

Ophthalmologica

Intrasession repeatability of optical coherence tomography measures in active neovascular age-related macular degeneration

Acta Ophthalmol

Repeatability of Spectralis OCT measurements of macular thickness and volume in diabetic macular edema

Invest Ophthalmol Vis Sci

Segmentation error and macular thickness measurements obtained with spectral-domain optical coherence tomography devices in neovascular age-related macular degeneration

Indian J Ophthalmol

Segmentation error in Stratus optical coherence tomography for neovascular age-related macular degeneration

Invest Ophthalmol Vis Sci

Pachychoroid diseases of the macula

Med Hypothesis Discov Innov Ophthalmol

Pachychoroid neovasculopathy

Retina

Reduced foveolar choroidal blood flow in eyes with increasing AMD severity

Invest Ophthalmol Vis Sci

Foveolar choroidal blood flow in age-related macular degeneration

Invest Ophthalmol Vis Sci

Choroidal thickness in polypoidal choroidal vasculopathy and exudative age-related macular degeneration

Ophthalmology

Original article
Spectral-domain Optical Coherence Tomography Retinal and Choroidal Thickness Metric Repeatability in Age-related Macular Degeneration