No significant differences of ocular and systemic hemodynamic
parameters were observed at baseline between study days
(Table 3) . Placebo had no consistent effect on systemic or ocular hemodynamic
parameters.
Mean blood pressure and PR were not significantly changed during
administration of BQ123
(Table 4) . Coefficients of variation for the ocular hemodynamic parameters,
calculated from the data of the placebo day, are presented in
Table 5 . The reproducibility was comparable between LDF-measurements in the
choroid and in the optic disc.
Effects of BQ123 on MFV in the ophthalmic artery are illustrated in
Figure 3 . Both doses of BQ123 significantly increased MFV in the ophthalmic
artery (after 60 minutes of infusion: 60 μg/kg · min: 12.5% ±
7.3%; 120 μg/kg · min: 17.2% ± 9.2%, versus baseline;
P = 0.001). No significant difference was observed
between the effects of the lower and the higher doses of BQ123 on MFV
(
P = 0.94).
Effects of BQ123 on hemodynamic parameters ONHBF and ChBF are presented
in
Figures 4 and 5 , respectively. In the ONH, blood flow (60 μg/kg · min: −0.9% ±
7.1%; 120 μg/kg · min: 1.6% ± 4.2%, versus baseline,
P = 0.982), volume (60 μg/kg · min: 6.6% ± 8.5%;
120 μg/kg · min: −0.04% ± 5.2%, versus baseline,
P = 0.575), and RBC velocity (60 μg/kg · min:−
2.1% ± 3.6%; 120 μg/kg · min: 3.1% ± 4.1% versus baseline;
P = 0.479) did not change significantly after
administration of BQ123 over 60 minutes. Similarly, blood flow (60μ
g/kg · min: 6.7% ± 6.5%; 120 μg/kg · min: −0.3% ± 5.4%,
versus baseline;
P = 0.201), volume (60 μg/kg ·
min: 6.8% ± 6.9%; 120 μg/kg · min: 3.3% ± 6.5%, versus
baseline;
P = 0.173), and RBC velocity (60 μg/kg ·
min: −1.5% ± 2.3%; 120 μg/kg · min: −2.3% ± 1.7%, versus
baseline;
P = 0.274), in the choroid did not change
significantly after administration of BQ123 over 60 minutes. IOP also
remained unchanged during ET
A receptor blockade
(60 μg/kg · min: −2.7% ± 4.1%; 120 μg/kg · min: −2.0% ±
4.8%, versus baseline;
P = 0.96).