Investigation of Ocular Blood Flow in Males with Metabolic Syndrome

Objectives: To investigate the effects of the ocular blood flow in male subjects with metabolic syndrome (MetS) by using laser speckle flowgraphy (LSFG). Methods: Subjects who underwent LSFG ocular blood flow testing during physical examinations were separated into the MetS group and the control group. The groups were propensity score-matched by age with 138 male subjects compared in each group. The subjects' ocular blood flow values (mean blur rate: MBR) in the optic nerve head (ONH) and choroid were measured by LSFG. We also measured pulse waveform parameters: the blowout score (BOS), blowout time (BOT), and rising rate (RR). The ONH region was measured as a whole, a tissue, and a vascular region. Results: MBR-Choroid was significantly lower in the MetS group versus the control group. For the ONH, there was no significant difference in the MBR. Compared to the control group in all regions, the RR values in the MetS group were significantly lower. The whole, tissue-region, and vascular-region BOS values were significantly higher in the MetS group. A single regression analysis revealed that only the number of MetS components was significantly negatively correlated with MBR-Choroid among the evaluated parameters. 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 the MBR in the choroid area at the early stage of MetS is decreasing in parallel with accumulation of MetS components. The MetS component with the strongest influence to the MBR-Choroid was HbA1c.