Purpose: To evaluate the quantification and reproducibility of circumpapillary vessel density (cpVD) measurements with swept-source optical coherence tomography angiography (SS-OCTA).
Methods: Eighteen healthy volunteers (36 eyes) were recruited at the Saitama Medical University Hospital between October and December 2017. A scan of the optic disc with SS-OCTA (PLEX™ Elite9000; Carl Zeiss Meditec) was performed twice on the same day. The cpVD in the superficial retinal layer (SRL), deep retinal layer (DRL), whole retinal layer (WRL), and projection artifact resolved DRL (PAR-DRL) images was calculated using binarization (Phansalkar), and intra-observer correlation coefficients (ICC) and coefficient of variation (CV) were calculated to evaluate the reproducibility of vessel density quantity between measurements.
Results: Thirty-three eyes of 18 volunteers were eligible for analysis. Cases of two eyes with suspected glaucoma and one eye of which image analysis was not possible due to image noise, were excluded. The average cpVD (%) of two measurements［median (quartile) ］was 74.9 (73.5-76.5) for SRL, 74.7 (72.6-75.3) for DRL, 27.4 (26.1-29.0) for PAR-DRL, and 81.5 (79.8-82.7) for WRL. The ICC and CV (%) ［mean (95% confidence interval) ］between measurements were 0.75 (0.56-0.87) and 0.78 (0.54-1.03) for SRL, 0.76 (0.57-0.87) and 0.81 (0.58-1.05) for DRL, 0.67 (0.43-0.82) and 2.65 (2.00-3.29) for PAR-DRL, and 0.70 (0.47-0.84) and 0.79 (0.56-1.01) for WRL, respectively.
Conclusion: SS-OCTA could quantify cpVD and demonstrated good reproducibility.
Nippon Ganka Gakkai Zasshi (J Jpn Ophthalmol Soc) 122: 685-692, 2018.