Introduction <p>Anti-vascular endothelial growth factor (VEGF) therapy suppresses neovascularization in neovascular age-related macular degeneration (nAMD) but may reduce ocular blood flow. However, its relationship with choroidal thickness remains unclear. This study evaluated 1-month outcomes after switching from intravitreal aflibercept or ranibizumab to intravitreal brolucizumab (IVBr) in patients with refractory nAMD.</p> Methods <p>This prospective, single-center study included 50 eyes of 50 patients with nAMD. Changes in best-corrected visual acuity (BCVA), central retinal thickness (CRT), subfoveal choroidal thickness (SFCT), choroidal vascularity index (CVI), choroidal stromal area (SA), choroidal luminal area (LA), optic nerve head (ONH) mean blur rate (MBR), and choroidal (CHOR) MBR were evaluated before and 1&#xa0;month after switching to IVBr, with blood flow measured using laser speckle flowgraphy. Univariate analyses were performed to identify potential predictors of changes in CHOR-MBR, and variables with <i>P</i> &lt; 0.1 were entered into a multiple regression model.</p> Results <p>BCVA was maintained. CRT decreased from 371.6 ± 118.7 to 288.8 ± 89.7&#xa0;µm (<i>P</i> &lt; 0.001). SFCT decreased from 231.9 ± 118.7 to 196.0 ± 117.4&#xa0;µm (<i>P</i> &lt; 0.001). CVI showed no significant changes, while SA and LA exhibited significant reductions. ONH-MBR and CHOR-MBR decreased (<i>P</i> = 0.004 and <i>P</i> &lt; 0.001, respectively). The baseline SFCT was the only significant predictor of change in CHOR-MBR. Older age correlated with thinner baseline SFCT and a greater decrease in CHOR-MBR.</p> Conclusions <p>IVBr is associated with significant reductions in CRT and SFCT and may decrease choroidal blood flow, particularly in older patients and those with thinner SFCTs.</p> Trial Registration <p>UMIN-CTR Registration ID, UMIN000041382.</p>