Comparison of the Repeatability of Macular Vascular Density Measurements Using Four Optical Coherence Tomography Angiography Systems.

Jingyuan Yang,Erqian Wang,Youxin Chen,Mingzhen Yuan

doi:10.1155/2019/4372580

Abstract

The aim of this study was to compare the repeatability of optical coherence tomography angiography (OCT-A) measurements of macular vessel density using four OCT-A systems, including Heidelberg Spectralis HRA, Optovue RTVue XR, Zeiss Cirrus HD-OCT 5000, and Topcon DRI OCT Triton. A cross-sectional design was used for this study. The vascular density and vascular length density of the superficial and deep retinal capillary plexuses were imaged with OCT-A using 3 mm and 6 mm scan patterns and were calculated using ImageJ. Comparisons of intraclass correlation coefficients (ICC) were conducted. We found that the OCT-A systems had various levels of repeatability. Zeiss had better repeatability for vessel density than the other systems (overall ICC = 0.936). Optovue had better repeatability for vessel length density when the 6 mm scan pattern was used (ICC = 0.680 and 0.700 for retinal superficial and deep capillary plexus, respectively). We concluded that repeatability varied when different scan patterns of various OCT-A systems were used for imaging the superficial retinal and deep capillary plexuses. Results should be seen as valid only for a given method. The repeatability of various OCT-A systems should be considered in clinical practice and in clinical trials that use OCT-A metrics as outcome measures.

Highlights

Optical coherence tomography angiography (OCT-A) was recently developed for imaging the retinal vasculature without dye injection [1]
No significant difference in intraclass correlation coefficients (ICC) values was noticed except for the ICC of the vessel density in the superficial capillary plexus (SCP) imaged with the 6 mm scan pattern using Zeiss; this suggests that the third-party software showed comparable or even better repeatability than the built-in software during analysis
No significant differences were observed between the ICCs of the vessel length density measurements derived with Optovue and Zeiss. e ICCs of the vessel length density of the SCP layer obtained using the 3 mm scan pattern in both Heidelberg and Topcon exceeded 0.6

Summary

Introduction

Optical coherence tomography angiography (OCT-A) was recently developed for imaging the retinal vasculature without dye injection [1]. OCT-A allows for the measurement of both the superficial and the deep retinal vessels quantitatively, including those in the macular region. Vessel density, which is quantified by calculating the percentage of the OCT image occupied by blood flow information as a fraction of the total image area, and vessel length density, which is quantified by calculating the percentage of skeletonized images of the retinal vasculature occupied by the vascular skeleton as a fraction of the total image area, have gained increasing popularity and represent promising quantitative metrics for future studies. Erefore, the repeatability of one OCT-A system should be taken into consideration when that OCT-A system is used None of these aforementioned studies compared the repeatability of macular vessel density measurements taken with different OCT-A systems in detail

Methods

Results

Discussion

Conclusion