Abstract
Purpose: :
Nebivolol is a third-generation beta-blocker with vasodilatory effects mediated by the endothelial release of NO. Vasodilative effects of Nebivolol have been reported in ocular and non-ocular vessels in several species. Main objective of the study was to evaluate the effect of a change in antihypertensive medication to Nebivolol on ocular perfusion in glaucoma patients.
Methods: :
The clinical trial was conducted as a mono-center, active-substance controlled, randomized, double-blind, prospective phase IV parallel group trial. Primary efficacy parameters were changes in the peak systolic velocity (PSV) and end-diastolic velocity (EDV) in the short and long posterior ciliary artery (SPCA, LPCA) recorded by color Doppler imaging (CDI) in the glaucoma patients before and 6 weeks after a change of systemic antihypertensive betablocker medication from Metoprolol to Nebivolol (5 mg) or Bisoprolol (5 mg). The Wilcoxon-Mann-Whitney test was applied for statistical analysis.
Results: :
19 patients completed the trial with n=10 in the Nebivolol and n=9 in the Bisoprolol group. No significant difference was observed between the two groups for any of the primary endpoints six weeks after the change in medication. Mean changes in the SPCA in the Nebivolol group were an increase of 2.0±2.2 cm/sec in the PSV (p=0.02) and 0.1±0.8 cm/sec in the EDV (p=0.98) versus an increase of 2.0±3.5 cm/sec in the PSV (p=0.10) and 1.0±1.3 cm/sec in the EDV (p=0.06) in the Bisoprolol group. IOP and systemic blood pressure remained unchanged.
Conclusions: :
Despite a significant increase in the PSV of the SPCA in the Nebivolol group, no significant differences were observed in retrobulbar blood flow velocities between the glaucoma patients receiving Nebivolol or Bisoprolol. Overall the results do not suggest a beneficial effect of Nebivolol on ocular perfusion, although the present study was impaired by a small sample size. The recruitment target was not achieved due to increasing number of patients with previous IOP-lowering operations. The potential of Nebivolol in the treatment of glaucoma patients with systemic hypertension merits further investigation in a larger study.
Clinical Trial: :
www.menarini.com, BCBe/04/Neb-Gla/081
Keywords: blood supply • nitric oxide • imaging methods (CT, FA, ICG, MRI, OCT, RTA, SLO, ultrasound)