Ocular Hemodynamic Effects of Nitrovasodilators in Healthy Subjects
试验速览
- 阶段
- 不适用
- 状态
- 已完成
- 入组人数
- 14
- 试验地点
- 1
- 主要终点
- Optic disc blood flow (laser Doppler flowmetry)
研究概览
简要总结
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.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Crossover
- 主要目的
- Basic Science
- 盲法
- Triple (Participant, Investigator, Outcomes Assessor)
入排标准
- 年龄范围
- 19 Years 至 35 Years（Adult）
- 性别
- Male
- 接受健康志愿者
- 是
入选标准
- •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.
排除标准
- •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
研究组 & 干预措施
1
Nitroglycerin: (Perlinganit, Nycomet Heilmittelwerke, Vienna, Austria):
0, 0.25, 0.5, 1, 1.5 and 2 µg/kg/min, each infusion step for 20 minutes
干预措施: Nitroglycerin (Drug)
2
Isosorbide-Dinitrate: (Isoket 0,1 %, Gebro Broschek, Fieberbrunn, Austria):
0, 0.5, 1, 2, 4 and 6 µg/kg/min , each infusion step for 20 minutes
干预措施: Isosorbide-Dinitrate (Drug)
3
Sodium-Nitroprusside: (Nipruss, Sanol-Schwarz, Monheim, Germany):
0, 0.25, 0.5, 1, 2 and 4 µg/kg/min, each infusion step for 20 minutes
干预措施: Sodium-nitroprusside (Drug)
4
Physiologic saline solution
干预措施: Physiologic saline solution (control substance) (Drug)
结局指标
主要结局
Optic disc blood flow (laser Doppler flowmetry)
时间窗: in total 24x on 4 study days
次要结局
- Intraocular pressure(in total 8x in 4 study days)
- Choroidal blood flow (laser Doppler flowmetry)(in total 24x on 4 study days)
- Fundus pulsation amplitude in the macula (laser interferometry)(in total 24x on 4 study days)
- Fundus pulsation amplitude in the optic disc (laser interferometry)(in total 24x on 4 study days)
- Blood pressure, pulse rate(on 4 study days)