Clinical trial NCT00810381: Ocular Hemodynamic Effects of Nitrovasodilators in Healthy Subjects
Official title: Ocular Hemodynamic Effects of Nitrovasodilators in Healthy Subjects
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Glaucoma
Keywords: Nitrovasodilators
ONH blood flow
Choroidal blood flow
Nitroglycerin
Isosorbide Dinitrate
Sodium nitroprusside
Laser-Doppler Flowmetry
Regional Blood Flow
Lead sponsor: Medical University of Vienna
Sponsor class: OTHER
First posted: 2008-12-18
Enrollment: 14
Sex: MALE
Minimum age (years): 19
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: Glaucoma, one of the most common causes of blindness, is associated with increased intraocular pressure (IOP) and optic nerve head ischemia. Nitrovasodilators are discussed in the treatment of glaucoma. Nitrates relax smooth muscle cells in the vasculature by liberating the vasodilator nitric oxide.

The IOP lowering potential and the vasodilator action in retinal and choroidal vessels of nitrates is still a matter of controversy. Previous studies on the ocular hemodynamic effects of nitrates showed partially contradicting results. In addition the IOP lowering effect of nitrates is still unclear. However, recent studies show that long acting nitrates may preserve optic nerve deterioration and visual field loss.

Therefore, the role of nitrovasodilators in control of ocular blood flow and intraocular pressure has to be elucidated. For this purpose the investigators plan to test the hypothesis that nitrovasodilators improve ocular blood supply to the optic nerve head at doses which do not affect systemic hemodynamics.


Eligibility criteria: Inclusion Criteria:

* Men aged between 19 and 35 years, nonsmokers
* Body mass index between 15th and 85th percentile (Must et al. 1991)
* Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
* Normal laboratory values unless the investigator considers an abnormality to be clinically irrelevant
* Normal ophthalmic findings, ametropia \< 3 Dpt.

Exclusion Criteria:

* Regular use of medication, abuse of alcoholic beverages, participation in a clinical trial in the 3 weeks preceding the study
* Treatment in the previous 3 weeks with any drug
* Symptoms of a clinically relevant illness in the 3 weeks before the first study day
* History of hypersensitivity to the trial drug or to drugs with a similar chemical structure
* History or presence of gastrointestinal, liver or kidney disease, or other conditions known to interfere with, distribution, metabolism or excretion of study drugs
* History of migraine
* Blood donation during the previous 3 weeks

Primary outcomes:
measure: Optic disc blood flow (laser Doppler flowmetry)
timeFrame: in total 24x on 4 study days
Secondary outcomes:
measure: Intraocular pressure
timeFrame: in total 8x in 4 study days
measure: Choroidal blood flow (laser Doppler flowmetry)
timeFrame: in total 24x on 4 study days
measure: Fundus pulsation amplitude in the macula (laser interferometry)
timeFrame: in total 24x on 4 study days
measure: Fundus pulsation amplitude in the optic disc (laser interferometry)
timeFrame: in total 24x on 4 study days
measure: Blood pressure, pulse rate
timeFrame: on 4 study days
Other outcomes:
Locations:
city: Vienna
country: Austria
facility: Department of Clinical Pharmacology, Medical University of Vienna
Study officials:
affiliation: Department of Clinical Pharmacology, Medical University of Vienna
name: Hans-Georg Eichler, MD
role: PRINCIPAL_INVESTIGATOR
References: