Ocular hemodynamic effects of nitrovasodilators in healthy subjects.
Nitric oxide (NO) plays a key role in the regulation of ocular blood flow and may be an interesting therapeutic target in ocular ischemic disease. In the present study, we hypothesized that NO-releasing drugs may increase blood flow to the head of the optic nerve and also in the choroid. The study employed a randomized, placebo-controlled, double blind, four-way crossover design. On separate study days, 12 healthy subjects received infusions of nitroglycerin, isosorbide dinitrate, sodium nitroprusside, or placebo. All three study drugs reduced the mean arterial pressure (MAP) and ocular perfusion pressure (OPP) (P < 0.001). None of the administered drugs increased the ocular hemodynamic variables. By contrast, vascular resistance decreased dose dependently during administration of the study drugs (P < 0.001). These results indicate that systemic administration of NO-donor drugs is associated with a decrease in vascular resistance in the ocular vasculature. However, because these drugs also reduce blood pressure, they do not improve perfusion to the posterior eye pole.
Schmidl
D
D
Department of Clinical Pharmacology, Medical University of Vienna, Vienna, Austria.
Polska
E
E
Kiss
B
B
Sacu
S
S
Garhofer
G
G
Schmetterer
L
L
D000328:Adult; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005500:Follow-Up Studies; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007429:Intraocular Pressure / Q000187:drug effects / Q000502:physiology; D008297:Male; D020030:Nitric Oxide Donors / Q000494:pharmacology*; D009900:Optic Nerve / Q000098:blood supply* / Q000187:drug effects* / Q000502:physiology; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D014655:Vascular Resistance / Q000187:drug effects / Q000502:physiology; D014665:Vasodilator Agents / Q000494:pharmacology*; D055815:Young Adult
D020030:Nitric Oxide Donors; D014665:Vasodilator Agents