Quantitative analysis of branching neovascular networks in polypoidal choroidal vasculopathy by optical coherence tomography angiography after photodynamic therapy and anti-vascular endothelial growth factor combination therapy.

Abstract

To study serial changes in branching neovascular networks (BNN) by using optical coherence tomography angiography (OCTA) in patients with polypoidal choroidal vasculopathy (PCV) who underwent combined photodynamic therapy (PDT) and anti-vascular endothelial growth factor (anti-VEGF) therapy. In this retrospective study of 30 PCV patients who underwent combined therapy, OCTA images obtained at baseline and 1, 3, and 6months after treatment were collected. The vessel area, vessel percentage area, average vessel length, and presence of polypoidal lesions on OCTA images as well as best-corrected visual acuity (BCVA), central retinal thickness (CRT), and central choroidal thickness (CCT) were recorded at each time point. The BNN- and polypoidal lesion-detection rates on baseline OCTA images were 100% and 71%, respectively. The vessel area decreased during the first 3months, and increased 6months post-treatment, showing significant differences from baseline (p = 0.031). The vessel percentage area also reduced 1 and 3months post-treatment (p = 0.025) and increased 6months post-treatment. Continuous polypoidal lesion regression was observed from 1 to 3 and 6months post-treatment (p = 0.031, p = 0.004, p = 0.002, respectively, in comparison with baseline). Patients with a decreasing vessel area over 6months showed greater choroidal thickness than those with increasing vessel area (p = 0.004). The BNN showed initial regression but were enlarged at 6months after therapy. Patients showing continuous BNN regression showed a thicker choroid at baseline. This difference should be considered during treatment for PCV, and OCTA could be used for follow-up evaluations of PCV patients.