Changes in retinal and choriocapillaris density in diabetic patients receiving anti-vascular endothelial growth factor treatment using optical coherence tomography angiography

BACKGROUND: Optical coherence tomography angiography (OCTA) enables detailed, non-invasive assessment of ocular vasculature. This study uses OCTA imaging to evaluate choriocapillaris and retinal capillary perfusion density (CPD) changes in diabetic retinopathy following anti-vascular endothelial growth factor (VEGF) treatment. METHODS: Records of 38 eyes at a single institution were reviewed, grouped as non-diabetic controls (19 eyes), diabetes mellitus patients with diabetic retinopathy (DR, 19 eyes) and macular edema (DME). DR eyes were imaged at baseline, 6-months and 12-months after anti-VEGF treatment. Quantitative analyses assessed CPD of the choriocapillaris and retinal plexus. RESULTS: DR eyes showed decreased choriocapillaris whole-image CPD (62.6 ± 6.1 vs. 68.4 ± 5.1, p < 0.003), foveal CPD (61.2 ± 7.4 vs. 66.3 ± 9.8, p < 0.014), and parafoveal CPD (61.9 ± 6.6 vs. 68.2 ± 4.8, p < 0.002) at baseline. DR eyes also showed decreased retinal density, including whole-image CPD (46.9 ± 5.1 vs. 50.7 ± 5.6, p < 0.04), foveal CPD (27.6 ± 5.9 vs. 34.1 ± 6.1, p < 0.002), and parafoveal CPD (49.0 ± 5.6 vs. 53.1 ± 6.0, p < 0.011). Following 12 months of anti-VEGF treatment, no changes to retinal or choriocapillaris or CPD were observed. Retinal central subfield thickness decreased (397.1 ± 93.2 µm vs. 294.2 ± 71.5 µm, p < 0.005). Lastly, FAZ area (0.307 ± 0.133 mm(2) vs. 0.184 ± 0.058 mm(2), p = 0.008) and perimeter (2.415 ± 0.692 mm(2) vs. 1.753 ± 0.408 mm(2), p = 0.002) were increased in DR eyes at baseline. No changes to FAZ area or perimeter were seen with anti-VEGF treatment in DR eyes. CONCLUSIONS: Compared to control, choriocapillaris and retinal CPD are reduced in DR, while FAZ area and perimeter are increased. No retinal capillary or choriocapillaris CPD changes were observed in DR eyes following anti-VEGF treatment.