The traditional kampo medicine tokishakuyakusan increases ocular blood flow in healthy subjects

Abstract

The aim of this study was to examine the effects of oral administration of kampo medical formulas on ocular blood flow (OBF). A crossover protocol was used to randomly administer five grams of yokukansan, tokishakuyakusan (TSS), keishibukuryogan, or hachimijiogan to 13 healthy blinded subjects (mean age: 37.3 ± 12.3 years). The mean blur rate, a quantitative OBF index obtained with laser speckle flowgraphy, was measured at the optic nerve head before and 30 minutes after administration. Blood pressure (BP) and intraocular pressure (IOP) were also recorded. No significant changes were observed in mean BP or IOP after the administration of any of the kampo medical formulas. There was a significant increase in OBF 30 minutes after administration of TSS (100% to 103.6 ± 6.9%, P < 0.01). Next, TSS was administered to 19 healthy subjects (mean age: 32.0 ± 11.0 years) and OBF was measured before and 15, 30, 45, and 60 minutes after administration. Plain water was used as a control. OBF increased significantly after TSS administration compared to control (P < 0.01) and also increased from 30 to 60 minutes after administration compared to baseline (P < 0.05). These results suggest that TSS can increase OBF without affecting BP or IOP in healthy subjects.

Figure 1

Dynamic OBF changes in response to administration of TSS (●) and control (○). Data are expressed as mean ± standard deviation. The dagger indicates a statistically significant difference between TSS and control (two-way analysis of variance; ANOVA). The asterisk indicates a statistically significant difference from the baseline (repeated measurements of ANOVA, with post hoc Dunnett's test).

Figure 2

Dynamic OBF changes in subjects with blood deficiency and blood stasis (a) and with blood deficiency and fluid retention (b) in response to administration of TSS. Data are expressed as mean ± standard deviation. The asterisk indicates a statistically significant difference from the baseline (repeated measurements of ANOVA, with post hoc Dunnett's test).

Figure 3

Representative MBR images of the entire ONH before administration and 30 and 60 minutes after the administration of TSS in healthy subjects (right eye). (a) Composite blood flow map of the ONH before the administration of TSS. The MBR value is 21.2. (b) Composite blood flow map of the ONH 30 minutes after the administration of TSS. The MBR value is 24.8. (c) Composite blood flow map of the ONH 60 minutes after the administration of TSS. The MBR value is 26.1.