The Standard Care vs Corticosteroid for Retinal Vein Occlusion (SCORE) study system for evaluation of optical coherence tomograms: SCORE study report 4

Abstract

Objective: To describe grading procedures for optical coherence tomographic (OCT) images of participants in the Standard Care vs Corticosteroid for Retinal Vein Occlusion (SCORE) Study.

Methods: Optical coherence tomograms were taken at clinical sites with the Stratus OCT using fast macular and crosshair scan protocols. Paper prints of images were evaluated at a central reading center. Quality evaluation identified the accuracy of OCT-measured retinal thickness data and was categorized as good, fair, borderline, or ungradable. Manual measurement of center point thickness was performed on borderline images. Morphological evaluation identified cystoid spaces, subretinal fluid, and vitreoretinal interface abnormalities. Reproducibility of grading was assessed through formal quality control exercises.

Results: A randomly selected set of 106 images was identified for quality control. The first 2 annual regrades showed 91% and 89% intergrader agreement for OCT quality. Intraclass correlation for manually measured center point thickness was 0.99 per year. For morphological variables, intergrader agreement for cystoid spaces was 83% and 76%. Reproducibility for subretinal fluid and vitreoretinal interface abnormalities could not be interpreted owing to their limited presence in the sample.

Conclusion: Optical coherence tomogram evaluation procedures used in the SCORE Study are reproducible and can be used for multicenter longitudinal studies of retinal vein occlusion.

Figure 1

Crosshair scan overlaid with a lateral scale for assessing lateral extent of morphological abnormalities. Dashed lines represent the limits of the central and the inner subfields on the B scan.

Figure 2

Quality categories for optical coherence tomograms.

Figure 3

Boundary line error affecting the retinal pigment epithelium with a wedge artifact on the false color map.

Figure 4

Decentered scan. The fovea is not in the center of the B scan and false color map. The 6 radial lines do not intersect at the anatomical fovea on the fundus image (lower right image).

Figure 5

Borderline category. Manual measurement of center point thickness in optical coherence tomography paper prints is shown. The mean (SD) optical coherence tomography–measured thickness is 319 (60) µm and is inaccurate owing to boundary line error at center point; caliper measurement (blue dots), 7.0 mm; computed retinal thickness at A scan (pink dots), 238 µm; caliper measurement, 6.7 mm; manually measured center point thickness=(238/6.7)×7.0=249 µm.