Optical Coherence Tomography Angiography Quality Across Three Multicenter Clinical Studies of Diabetic Retinopathy

To explore optical coherence tomography angiography (OCTA) quality and associated factors in multicenter clinical studies. OCTA scans were obtained from participants with diabetic retinopathy from three DRCR Retina Network clinical studies using the Optovue AngioVue and ZEISS AngioPlex. Macular (3 × 3 mm and 6 × 6 mm) and optic nerve scans were captured. Quality was assessed by the Casey Reading Center. Scans were considered "poor" if the signal strength index (SSI) was less than 55 (AngioVue) or 7 (AngioPlex) or if excess motion, media opacities, beam defocus, incorrect axial position, or other artifacts were present. Included were 7539 scans from 787 eyes (461 participants). Sixty-one percent of scans were considered "good" (n = 4630). Of the 3 × 3-mm (n = 2294), 6 × 6-mm (n = 2705), and optic nerve scans (n = 2540), 62%, 63%, and 59%, respectively, were good. Differences in percentage of good scans by machine were not identified (61% of 6216 for the AngioVue and 63% of 1323 for the AngioPlex). The primary reason for poor scans was low SSI for the AngioVue (67%) and excess motion for the AngioPlex (47%). Good scans were associated with younger age (60 ± 12 years vs. 65 ± 11 years; P < 0.001), male gender (64% of males had good scans vs. 57% female; P = 0.007), and better visual acuity (ETDRS letter score 86.5 ± 6.4 [approximate Snellen equivalent 20/20] vs. 81.6 ± 9.7 [approximate Snellen equivalent 20/25]; P < 0.001). Scan quality or analysis must be improved for OCTA metrics to be used as outcomes in future research. Clinicians and researchers should be aware that poor SSI and artifacts are common issues for OCTA images.