What is the repeatability and reproducibility of quantitative superficial macular retinal vessel density data from optical coherence tomographic angiography?
In this cross-sectional study of 21 healthy volunteers and 22 patients with retinal disease, the coefficient of variation was less than 6% among consecutive scans and among different devices. The agreement was highest for the 3 × 3-mm scan pattern for the inner ring and 6 × 6-mm scan pattern for the outer ring, and signal strength and scan pattern had a significant influence on the measurements.
The findings of this study might provide useful information for future clinical trials involving optical coherence tomographic angiography.
The repeatability and reproducibility of quantitative metrics from optical coherence tomographic angiography (OCTA) must be assessed before these data can be confidently interpreted in clinical research and practice.
To evaluate the repeatability and reproducibility of OCTA-derived retinal vascular quantitative metrics.
Design, Setting and Participants
In this cross-sectional study, 21 healthy volunteers (42 eyes) and 22 patients with retinal disease (22 eyes), including 14 with age-related macular degeneration, 3 with epiretinal membrane, 2 with diabetic retinopathy, 2 with myopic macular degeneration, and 1 with retinal vein occlusion, were enrolled. Participants were recruited from September 1 through November 31, 2016. Each eye underwent 3 repeated scans with 3 instruments for a total of 9 acquisitions. Eyes were randomly assigned to scanning with a 3 × 3-mm or 6 × 6-mm pattern. Eyes were excluded from subsequent analysis if any acquisition had a signal strength of less than 7. Repeatability (defined as the agreement in measurements within a device) and reproducibility (defined as the agreement between devices of the same type) were assessed by intraclass correlation coefficient (ICC) and coefficient of variation.
All eyes underwent scanning using 3 separate devices.
Main Outcomes and Measures
Vessel length density (VLD) and perfusion density (PD) of the superficial retinal vasculature.
A total of 21 healthy volunteers (8 men and 13 women; mean [SD] age, 36  years) and 22 patients with retinal disease (15 men and 7 women; mean [SD] age, 79  years) underwent evaluation. Of these, 40 of 42 normal eyes and 15 of 22 eyes with retinal disease met signal strength criteria and were included in this analysis. The ICC among the 3 consecutive scans ranged from 0.82 to 0.98 for VLD and from 0.83 to 0.95 for PD. The coefficient of variation (CV) ranged from 2.2% to 5.9% for VLD and from 2.4% to 5.9% for PD. For reproducibility, the ICC ranged from 0.62 to 0.95 and the CV was less than 6% in all groups. The agreement was highest for the 3 × 3-mm pattern in the inner ring (ICC range, 0.92 [95% CI, 0.85-0.96] to 0.96 [95% CI, 0.93-0.98]) and 6 × 6-mm pattern in the outer ring (ICC range, 0.93 [95% CI, 0.86-0.97] to 0.96 [95% CI, 0.92-0.98]).
Conclusions and Relevance
Vessel length density and PD of the superficial retinal vasculature can be obtained from OCTA images with high levels of repeatability and reproducibility but can vary with scan pattern and location.
Lei J, Durbin MK, Shi Y, Uji A, Balasubramanian S, Baghdasaryan E, Al-Sheikh M, Sadda SR. Repeatability and Reproducibility of Superficial Macular Retinal Vessel Density Measurements Using Optical Coherence Tomography Angiography En Face Images. JAMA Ophthalmol. Published online September 14, 2017. doi:10.1001/jamaophthalmol.2017.3431