Comparison of neovascular lesion area measurements from different swept-source OCT angiographic scan patterns in age-related macular degeneration

PURPOSE. We compared area measurements for the same neovascular lesions imaged using swept source optical coherence tomography angiography (SS-OCTA) and enlarging scan patterns. METHODS. Patients with neovascular age-related macular degeneration were imaged using a 100-kHz SS-OCTA instrument (PLEX Elite 9000). The scanning protocols included the 3 × 3, 6 × 6, 9 × 9, and 12 × 12 mm fields of view. Two groups were studied. Group 1 included small lesions contained within the 3 × 3 mm scan, and Group 2 included larger lesions that were fully contained within the 6 × 6 mm scan. RESULTS. A total of 30 eyes of 26 patients were enrolled in Group 1 and 30 eyes of 25 patients were enrolled in Group 2. In Group 1, the automated mean lesion area measurements were 1.11 (SD = 0.78), 1.14 (SD = 0.80), and 1.27 (SD = 0.82) mm² for the 3 × 3, 6 × 6, and 12 × 12 mm scans, respectively (ANOVA P < 0.001; post hoc comparisons, P = 0.184, 3 × 3 vs. 6 × 6 mm; P < 0.001 for the other two pairs). In Group 2, the automated mean lesion area measurements were 5.43 (SD = 2.56), 5.53 (SD = 2.48), and 5.49 (SD = 2.65) mm² for the 6 × 6, 9 × 9, and 12 × 12 mm scans, respectively (ANOVA P = 0.435; post-hoc comparisons, P = 0.062, 6 × 6 vs. 9 × 9 mm; P = 0.553, 6 × 6 vs. 12 × 12 mm; P = 0.654, 9 × 9 vs. 12 × 12 mm). CONCLUSIONS. The similarity in lesion area measurements across different scan patterns suggests that SS-OCTA imaging can be used to follow quantitatively the enlargement of choroidal neovascularization as the disease progresses.