Effect of Optical Coherence Tomography Angiography Image Artifacts on Quantitation of Vessel Density and Perfusion

BACKGROUND AND OBJECTIVE: This study aimed to quantify the effects of four common artifacts of optical coherence tomography angiography (OCTA) on metrics of perfusion. PATIENTS AND METHODS: Data from the Framingham Heart Study were reviewed to select consecutive OCTA scans with and without representative image artifacts. Four artifact categories were defined (decentration, motion, shadowing, defocus) and graded using a severity scale of "Not Present," "Mild," or "Severe." Multivariate linear mixed-effects models were used to assess the impact of each artifact on vessel skeleton density (VSD), vessel area density (VAD), and flux. RESULTS: The study included 141 OCTA scans from 20 participants. Severe shadowing or any severity of defocus significantly attenuated all OCTA parameters. Severe decentration significantly attenuated VAD and flux, but not VSD. Motion artifacts and mild decentration had no significant effects. CONCLUSION: Image defocus and shadowing significantly affect all OCTA measures. VSD is the most robust measure against most artifacts.