Significant Correlation Between Choroidal Thickness and Decrease in Choroidal Blood Flow After Switching to...

Area of Science:

• Ophthalmology
• Retinal Diseases
• Vascular Biology

Background:

• Anti-vascular endothelial growth factor (VEGF) therapy is standard for neovascular age-related macular degeneration (nAMD).
• VEGF inhibitors may impact ocular blood flow and choroidal thickness, with unclear clinical implications.
• This study investigates outcomes after switching to intravitreal brolucizumab (IVBr) in refractory nAMD.

Purpose of the Study:

• To evaluate the 1-month effects of switching from aflibercept or ranibizumab to IVBr in patients with refractory nAMD.
• To assess changes in visual acuity, retinal thickness, choroidal thickness, and choroidal blood flow.
• To identify predictors of changes in choroidal blood flow.

Main Methods:

• Prospective, single-center study of 50 eyes with nAMD.
• Evaluated best-corrected visual acuity (BCVA), central retinal thickness (CRT), subfoveal choroidal thickness (SFCT), and choroidal blood flow (CHOR-MBR) before and 1 month after IVBr treatment.
• Laser speckle flowgraphy used for blood flow measurement; regression analyses performed to identify predictors of CHOR-MBR changes.

Main Results:

• BCVA was maintained; CRT and SFCT significantly decreased (P < 0.001).
• Choroidal stromal area and luminal area significantly reduced; choroidal vascularity index unchanged.
• Optic nerve head and choroidal blood flow (ONH-MBR and CHOR-MBR) decreased significantly (P = 0.004 and P < 0.001, respectively).
• Baseline SFCT was the sole significant predictor of CHOR-MBR change; older age correlated with thinner SFCT and greater CHOR-MBR reduction.

Conclusions:

• Intravitreal brolucizumab (IVBr) treatment leads to significant reductions in retinal and choroidal thickness in nAMD.
• IVBr may decrease choroidal blood flow, particularly in older individuals and those with thinner baseline subfoveal choroidal thickness.
• Further research is needed to understand long-term implications of IVBr on ocular hemodynamics.