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OpenTrials
Completed

NCT Number: NCT00810381

Ocular Hemodynamic Effects of Nitrovasodilators in Healthy Subjects

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.

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Key information

Conditions

Glaucoma Eye Diseases Ocular Hypertension

Age range

19 year–35 year

Sex eligibility

Male

Study type

Interventional

Phase

Not applicable

Primary location

Department of Clinical Pharmacology, Medical University of Vienna

Vienna, 1090, Austria

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

Nitroglycerin

Drug

intravenous infusion; 0, 0.125, 0.25, 0.5, 1 and 2 µg/kg/min; 20 minutes per infusion step

Isosorbide-Dinitrate

Drug

intravenous infusion; 0, 0.5, 1, 2, 4, and 6 µg/kg/min; 20 minutes per infusion step

Sodium-nitroprusside

Drug

intravenous infusion; 0, 0.25, 0.5, 1, 2, and 4 µg/kg/min; 20 minutes per infusion step

Physiologic saline solution (control substance)

Drug

intravenous infusion, infusion period 120 minutes

Primary outcomes

  1. Optic disc blood flow (laser Doppler flowmetry)

    Time frame: in total 24x on 4 study days

Secondary outcomes

  1. Intraocular pressure

    Time frame: in total 8x in 4 study days

  2. Choroidal blood flow (laser Doppler flowmetry)

    Time frame: in total 24x on 4 study days

  3. Fundus pulsation amplitude in the macula (laser interferometry)

    Time frame: in total 24x on 4 study days

  4. Fundus pulsation amplitude in the optic disc (laser interferometry)

    Time frame: in total 24x on 4 study days

  5. Blood pressure, pulse rate

    Time frame: on 4 study days

Sponsors and collaborators

Lead sponsor

Medical University of Vienna

Other

Registry information

Important dates

Study start
1999
Primary completion
1999
Study completion
1999
First posted
Dec 18, 2008
Registry last updated
Dec 18, 2008

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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