Impact of Androgen Deprivation Therapy on Choroidal Microcirculation Assessed Using Laser Speckle Flowgraphy

ABSTRACT Objective To determine whether androgen deprivation therapy (ADT) alters laser speckle flowgraphy (LSFG)‐detectable choroidal microvascular dynamics: mean blur rate (MBR, blood flow) and beat strength over MBR (BOM, microvascular resistance). We also investigated whether such changes emerge even when cardio‐ankle vascular index (CAVI)‐assessed large‐artery stiffness remains unchanged. Methods This study included 17 right eyes of 17 men with prostate cancer. Serum testosterone, CAVI, and choroidal parameters (MBR, BOM) were obtained at baseline and 6 months post‐ADT. Central choroidal thickness (CCT) and ocular perfusion pressure (OPP) were also recorded. Results Serum testosterone significantly decreased (4.45 ± 1.96 to 0.20 ± 0.08 ng/mL; p < 0.001) after 6 months. Choroidal BOM increased significantly (0.94 ± 0.31 to 1.11 ± 0.31; p = 0.028), whereas CAVI (10.70 ± 1.28 to 10.68 ± 1.19), choroidal MBR (8.46 ± 4.50 to 7.89 ± 3.48), CCT, and OPP did not change significantly. Conclusion Choroidal BOM increased significantly during the initial 6 months of ADT, indicating higher microvascular resistance despite stable choroidal blood flow and unchanged large artery stiffness. This supports a “microcirculation‐first” model. LSFG‐derived BOM may serve as a biomarker for early detection and monitoring of microcirculatory dysfunction under systemic testosterone suppression.