Purpose: To investigate disease activity in patients with Type 3 neovascularization undergoing anti-vascular endothelial growth factor treatment through image analysis using optical coherence tomography angiography (OCTA).
Methods: Thirty-nine treatment-naive eyes with Type 3 neovascularization were included in the retrospective analysis. All patients were treated with three loading injections of an anti-vascular endothelial growth factor agent, followed by further injections as needed. Changes in the Type 3 lesion were analyzed through OCTA imaging during the 12 months of follow-up.
Results: The high-flow signal of Type 3 neovascularization on OCTA images disappeared in 46.2% eyes (19 of 39) and was persistent in 53.8% eyes (20 of 39) after loading injections. A persistent high-flow signal on OCTA after treatment was found at the sub-retinal pigment epithelium in 65.0% eyes (13 of 20), deep vascular plexus in 30.0% eyes (6 of 20), and outer neurosensory retina in 15.0% eyes (3 of 20). Eyes without lesions on OCTA images received significantly fewer injections (3.7 vs. 5.5; P = 0.016) and showed a longer retreatment-free period (mean 7.57 vs. 4.07 months; P = 0.002) during the 12-month follow-up than eyes with a persistent high-flow signal on OCTA. However, no significant between-group difference was observed in terms of improved visual acuity.
Conclusion: Patients with Type 3 neovascularization who had no lesion on an OCTA scan after anti-vascular endothelial growth factor treatment showed a lower recurrence rate and maintained visual acuity with fewer injections than those with persistent high-flow lesions on an OCTA scan. Optical coherence tomography angiography may provide an additional biomarker for clinical guidance in the treatment and monitoring of disease activity in Type 3 neovascularization.