The Importance of Signal Strength in Quantitative Assessment of Retinal Vessel Density Using Optical Coherence Tomography Angiography by Jung Yeul Kim, South Korea


The quality of the scan image is important in microvascular circulation analysis using optical coherence tomography (OCTA). We aimed to investigate the effect of signal strength (SS) on OCTA metrics and minimum SS level that could be considered optimal. Macular 6x6mm angiography images were acquired, and all subjects were divided into four groups according to the SS (SS 7, SS 8, SS 9, and SS 10) of the OCTA image. Vessel density (VD), perfusion de nsity (PD), and foveal avascular zone (FAZ) metrics of the superficial capillary plexus were compared. In total, 292 eyes from young healthy subjects were included. As the SS increased from 7 to 10, the VD and PD of the total area, and the FAZ area increased significantly (all, p<0.001), but there were no significant difference between SS 9 and SS10 in all metrics. Correlation analysis between the SS and each parameter showed a high correlation coefficient (VD, r=0.668; PD, r=0.671; FAZ area, r=0.570; all, p<0.001). The measurements of VD, PD, and FAZ using OCTA varied significantly with the SS, and at least 9 of SS is recommended. The physician should be careful in the analyses of OCTA measurements showing different values of the SS.


Jung Yeul Kim
Chungnam National University Hospital
South Korea
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