Ocular Hemodynamic Effects of Nitrovasodilators in Healthy Subjects

Glaucoma Clinical Trial

Official title:

Ocular Hemodynamic Effects of Nitrovasodilators in Healthy Subjects

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00810381
• Other study ID #: OPHT-211097
• Status: Completed
• Phase: N/A
• First received: December 17, 2008
• Last updated: December 17, 2008
• Start date: January 1999
• Est. completion date: June 1999

Study information

• Verified date: December 2008
• Source: Medical University of Vienna
• Contact: n/a
• Is FDA regulated: No
• Health authority: Austria: Agency for Health and Food Safety
• Study type: Interventional

Clinical Trial 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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 14
• Est. completion date: June 1999
• Est. primary completion date: June 1999
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: Male
• Age group: 19 Years to 35 Years

Eligibility

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

Study Design

Allocation: Randomized, Endpoint Classification: Safety/Efficacy Study, Intervention Model: Crossover Assignment, Masking: Double Blind (Subject, Investigator, Outcomes Assessor), Primary Purpose: Basic Science

Related Conditions & MeSH terms

• Glaucoma

Intervention

Drug:
• Nitroglycerin
intravenous infusion; 0, 0.125, 0.25, 0.5, 1 and 2 µg/kg/min; 20 minutes per infusion step
• Isosorbide-Dinitrate
intravenous infusion; 0, 0.5, 1, 2, 4, and 6 µg/kg/min; 20 minutes per infusion step
• Sodium-nitroprusside
intravenous infusion; 0, 0.25, 0.5, 1, 2, and 4 µg/kg/min; 20 minutes per infusion step
• Physiologic saline solution (control substance)
intravenous infusion, infusion period 120 minutes

Locations

Country	Name	City	State
Austria	Department of Clinical Pharmacology, Medical University of Vienna	Vienna

Sponsors (1)

Lead Sponsor	Collaborator
Medical University of Vienna

Country where clinical trial is conducted

Austria, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Optic disc blood flow (laser Doppler flowmetry)		in total 24x on 4 study days	No
Secondary	Intraocular pressure		in total 8x in 4 study days	No
Secondary	Choroidal blood flow (laser Doppler flowmetry)		in total 24x on 4 study days	No
Secondary	Fundus pulsation amplitude in the macula (laser interferometry)		in total 24x on 4 study days	No
Secondary	Fundus pulsation amplitude in the optic disc (laser interferometry)		in total 24x on 4 study days	No
Secondary	Blood pressure, pulse rate		on 4 study days	Yes