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

Purpose: 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.

Methods: In this retrospective study of 30 PCV patients who underwent combined therapy, OCTA images obtained at baseline and 1, 3, and 6 months 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.

Results: The BNN- and polypoidal lesion-detection rates on baseline OCTA images were 100% and 71%, respectively. The vessel area decreased during the first 3 months, and increased 6 months post-treatment, showing significant differences from baseline (p = 0.031). The vessel percentage area also reduced 1 and 3 months post-treatment (p = 0.025) and increased 6 months post-treatment. Continuous polypoidal lesion regression was observed from 1 to 3 and 6 months post-treatment (p = 0.031, p = 0.004, p = 0.002, respectively, in comparison with baseline). Patients with a decreasing vessel area over 6 months showed greater choroidal thickness than those with increasing vessel area (p = 0.004).

Conclusions: The BNN showed initial regression but were enlarged at 6 months 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.