Using optical coherence tomography angiography in assessment of the anti-vascular endothelial growth factor effect for pathological vascular tissue in age-related macular degeneration and polypoidal choroidal vasculopathy
Authors: Shen Yi-Syun , Cheng Cheng-Kuo 
Published: March 2020

Purpose: Using optical coherence tomography angiography to assess and compare changes in pathological vascular tissue, including choroidal neovascularization in neovascular age-related macular degeneration and polypoidal complex in polypoidal choroidal vasculopathy, after treatment with anti-vascular endothelial growth factor. Methods: This is a retrospective observational case series study. Clinical data were collected, including that on the best-corrected visual acuity and images of spectrum domain optical coherence tomography and optical coherence tomography angiography of consecutive patients with macula-involved lesions, active pathological vascular tissue in neovascular age-related macular degeneration, and polypoidal complex in polypoidal choroidal vasculopathy who were treated with anti-vascular endothelial growth factor injection. The primary outcome measures were the lesion area, flow density, and flow area of the pathological vascular tissue obtained in optical coherence tomography angiography before treatment, as well as week-1 (W1) and week-5 (W5) after treatment. The secondary outcome measures were the best-corrected visual acuity and the anatomic changes in spectrum domain optical coherence tomography at the same periods. Results: A total of 86 eyes in 79 patients (mean age: 73.10 ± 10.10 (range = 50–91) years, 45 males (57%), of which two eyes were treatment-naïve) underwent one section of intravitreal treatment. Of which 44 eyes (40 patients) were diagnosed as typical neovascular age-related macular degeneration and 42 eyes (39 patients) as polypoidal choroidal vasculopathy. The sensitivity for detecting choroidal neovascularization in neovascular age-related macular degeneration and polypoidal complex in polypoidal choroidal vasculopathy was 75.00% (33/44) and 69.05% (29/42), respectively. There was no significant difference in the detection rate between neovascular age-related macular degeneration and polypoidal choroidal vasculopathy ( p = 0.54). In the detectable group, there were significant decrease in lesion area and flow area in the optical coherence tomography angiography images after anti-vascular endothelial growth factor treatment in both the neovascular age-related macular degeneration group (lesion area: W1 = –26.94 ± 19.50%, W5 = –35.52 ± 30.85%, all ps < 0.001; flow area: W1 = –26.22 ± 25.23%, W5 = –32.24 ± 32.07%, all ps < 0.001) and the polypoidal choroidal vasculopathy group (lesion area: W1 = –25.19 ± 20.27%, W5 = –31.55 ± 27.04%, all ps < 0.001; flow area: W1 = –21.83 ± 26.29%, W5 = –28.31 ± 30.72%, all ps < 0.001). The central subfield retinal thickness in spectrum domain optical coherence tomography also showed similar amelioration in both groups. However, the flow density in optical coherence tomography angiography image and the visual outcome did not reveal any significant difference before or after intravitreal injections, and neither were there significant differences between the neovascular age-related macular degeneration and polypoidal choroidal vasculopathy groups. Concerning the effect on the optical coherence tomography angiography images of pathological vascular tissue, there were no statistical differences among different anti-vascular endothelial growth factor agents (i.e. aflibercept, ranibizumab, and bevacizumab). Conclusion: Our study revealed that optical coherence tomography angiography can be used noninvasively and quantitatively to assess the detailed pathologic vascular structures in both neovascular age-related macular degeneration and polypoidal choroidal vasculopathy. Our study also demonstrated that anti-vascular endothelial growth factor could effectively decrease the lesion size and flow area of both the choroidal neovascularization in neovascular age-related macular degeneration cases and the polypoidal complex in polypoidal choroidal vasculopathy cases; the effects were similar in both diseases.