Increased peripapillary choroidal blood flow velocity in peripapillary pachychoroid syndrome: Three case reports with referential observations in central serous chorioretinopathy

Choroidal blood flow velocity in the macula increases during the acute phase of central serous chorioretinopathy (CSC). This study aimed to report the distribution of choroidal blood flow velocity in three patients with peripapillary pachychoroid syndrome (PPS) and to present referential hemodynamic data from eyes with CSC and healthy controls. Two males and one female were diagnosed with PPS. Using laser speckle flowgraphy, the mean blur rate (MBR)—an index of relative blood flow velocity—was measured at the macula and points 1.5 mm (N1.5) and 3.0 mm (N3.0) nasal to the fovea in all patients (three eyes) with PPS, 28 patients (30 eyes) with CSC, and 27 age- and sex-matched healthy controls. The MBR ratios for N1.5 and N3.0, relative to the macula, were calculated for each group. The MBR ratio at N3.0 relative to the macula was < 1.0 in both the CSC (0.76 ± 0.18) and control (0.71 ± 0.20) groups, with no significant difference between the two groups ( P = 0.326). In contrast, the ratio in the PPS group was 1.45 ± 0.22, which is approximately 1.9–2.0 times higher than in the other groups, although no statistical comparisons were performed due to the imbalance in group sizes. The N1.5-to-macula MBR ratios were similar across the three groups. and importance : These findings suggest elevated choroidal blood flow velocity at the lesion site in PPS, as reflected by a higher MBR in the temporal peripapillary region compared to the macula. This distinct MBR distribution may serve as a valuable diagnostic marker for PPS. Claim of Priority: A literature review was conducted on July 1, 2025, using PubMed, Google Scholar, and Scopus with the keywords “peripapillary pachychoroid syndrome (PPS),” “laser speckle flowgraphy,” and “choroidal blood flow velocity.” No prior reports were identified that quantitatively assessed choroidal hemodynamics in PPS.