Repeatability of choroidal thickness measurements with Spectralis OCT images

Abstract

ObjectiveTo investigate the repeatability of choroidal thickness measurements determined from enhanced depth imaging optical coherence tomography (EDI-OCT) images of eyes after wearing single-vision spectacles (SV) and orthokeratology (ortho-k) lenses.Methods and analysisTwo EDI-OCT images of 40 children (SV: 20, ortho-k: 20) taken at a single visit were analysed twice. Subjects in the ortho-k group had been wearing ortho-k for 1–4 weeks. The choroidal thickness was determined from each image using a graph theory-based software and, where appropriate, manual correction of choroidal boundaries was undertaken by an experienced examiner.ResultsThe mean (±SD) choroidal thickness was 227.3±42.2 µm for the SV subjects and 251.1±54.4 µm for the ortho-k subjects. The interimage differences in choroidal thickness were −0.99±3.54 and −1.14±5.03 µm for the SV and ortho-k subjects, respectively, and the limits of agreement were +5.96 to −7.93 and +8.72 to −11.00 µm, respectively.ConclusionThe coefficients of repeatability of choroidal thickness measurements from two EDI-OCT images taken at a single visit were 7.08 µm (SV) and 10.06 µm (ortho-k), suggesting that a change in choroidal thickness of less than 10 µm may not indicate a real change resulting from ortho-k lens wear.

Weekly Changes in Axial Length and Choroidal Thickness in Children During and Following Orthokeratology Treatment With Different Compression Factors

“…Li et al18 also suggested that the subfoveal choroidal thickening during orthokeratology treatment probably served as a predictor for the long-term effectiveness of the treatment. However, despite the choroidal changes observed and their significance in the statistical model in this study, the interimage (examining two chorio-retinal images captured from the same eye in the same measurement session) coefficient of repeatability of the subfoveal choroidal thickness measurement using a semiautomated method in orthokeratology-treated subjects was only 10 μm 35. This implies that the maximum mean treatment group changes observed in this study approached the coefficient of interimage repeatability of our technique, and therefore there is some uncertainty whether the observed changes in choroidal thickness are genuine.…”

BCLA CLEAR - Orthokeratology

“…A greater initial choroidal thickening after commencing ortho-k is associated with less axial eye growth over a one year period [368], which suggests that short-term changes in the choroid may be a biomarker for longer-term eye growth. While some commercially available posterior segment optical coherence tomographers allow high resolution imaging of the retina and choroid (~4 μm axial resolution), the intraobserver and inter-scan coefficient of repeatability for measures of subfoveal choroidal thickness is ~10 to 20 μm in children [369,373] and adults [374][375][376]. Improvements in optical coherence tomography imaging, such as higher wavelength instruments that allow enhanced imaging of the choroid-scleral interface or automated image analysis procedures that improve choroidal segmentation, may be of benefit in future studies of choroidal thickness in children treated with ortho-k.…”

Repeatability and inter‐observer variation of choroidal thickness measurements using swept‐source optical coherence tomography in myopic danish children aged 6–14 years

“…Enhanced depth imaging OCT with a star scan consisting of six line scans radially centred at the fovea was used. They found CRs of 7.08 and 10.06 µm for SVS and OKL, respectively (Lau et al 2019). The second study was on healthy young adults using enhanced-depth imaging OCT centred at the fovea covering 55°9 45°containing 37 horizontal line scans.…”