Investigation of Ocular Blood Flow in Males with Metabolic Syndrome

Objectives: This study aims to investigate ocular blood flow in male subjects with metabolic syndrome (MetS) using laser speckle flowgraphy (LSFG). Methods: Subjects who underwent LSFG ocular blood flow testing during physical examinations were separated into a MetS group and a control group. The groups were propensity score-matched by age, with 138 male subjects compared in each group. The subjects' ocular blood flow (mean blur rate, MBR) in the optic nerve head (ONH) and choroid was measured via LSFG. Pulse waveform parameters, the blowout score (BOS), blowout time (BOT), and rising rate (RR), were also measured. The ONH region was measured as a whole and as tissue and vascular regions. Results: The MBR-Choroid was significantly lower in the MetS group versus the control group. There was no significant difference in the MBR in the ONH. Compared to the control group, the RR values in the MetS group were significantly lower in all regions. The whole tissue region and vascular region BOS values were significantly higher in the MetS group. A single-regression analysis revealed that among the evaluated parameters, only the number of MetS components was significantly negatively correlated with the MBR-Choroid. A multiple regression analysis identified HbA1c as a factor contributing independently to the MBR-Choroid among the MetS-related factors. Conclusions: This investigation of adult males clarified that in the early stage of MetS, the MBR in the choroid area decreases in parallel with the accumulation of MetS components. The MetS component with the strongest influence on the MBR-Choroid was HbA1c.