Effects of Common Topical Glaucoma Therapy on Optic Nerve Head Blood Flow Autoregulation During Increased Arterial Blood Pressure and Artificially Elevated Intraocular Pressure in Healthy Humans
试验速览
- 阶段
- 不适用
- 状态
- 撤回
- 试验地点
- 1
- 主要终点
- Ocular perfusion pressure - ONH blood flow relationship
研究概览
简要总结
Background
Autoregulation is the ability of a vascular bed to maintain blood flow despite changes in perfusion pressure. The existence of an effective autoregulation in the optic nerve circulation has been shown in animals and humans. The exact mechanism behind this autoregulation is still unknown. The motive for the investigation of optic nerve head (ONH) blood flow autoregulation is to enhance the understanding of pathologic eye conditions associated with ocular vascular disorders. To clarify the regulatory mechanisms of ONH microcirculation is of critical importance to understand the pathophysiology of glaucoma, because there is evidence that glaucoma is associated with optic nerve head ischemia. Several studies indicate that a disturbed autoregulation might contribute to glaucomatous optic neuropathy. Currently, five classes of intraocular pressure (IOP) reducing drugs are available for topical therapy in patients with glaucoma or elevated intraocular pressure. These drugs have also vasoactive properties, which may influence both the resting ocular circulation and the autoregulatory mechanisms of blood flow during changes in ocular perfusion pressure.
Study objective
To investigate the influence of common topical glaucoma therapy on ONH blood flow regulation during changes in IOP and systemic arterial blood pressure.
研究设计
- 研究类型
- Interventional
- 分配方式
- Randomized
- 干预模型
- Parallel
- 主要目的
- Basic Science
- 盲法
- Double (Participant, Investigator)
入排标准
- 年龄范围
- 19 Years 至 35 Years（Adult）
- 性别
- All
- 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
- •Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
- •Normal ophthalmic findings, ametropia < 1 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
- •Blood donation during the previous 3 weeks
- •Presence of intraocular pathology: ocular hypertension, glaucoma, retinal vasculopathy or other retinal diseases
研究组 & 干预措施
1
干预措施: Timolol (drug) (Drug)
1
干预措施: Laser Doppler flowmetry (Device)
1
干预措施: Goldmann applanation tonometer (Device)
1
干预措施: Suction cup method (Procedure)
2
干预措施: dorzolamide (drug) (Drug)
2
干预措施: Laser Doppler flowmetry (Device)
2
干预措施: Goldmann applanation tonometer (Device)
2
干预措施: Suction cup method (Procedure)
3
干预措施: brimonidine (drug) (Drug)
3
干预措施: Laser Doppler flowmetry (Device)
3
干预措施: Goldmann applanation tonometer (Device)
3
干预措施: Suction cup method (Procedure)
结局指标
主要结局
Ocular perfusion pressure - ONH blood flow relationship
时间窗: on 2 study days
次要结局
- Composite measure: Blood pressure, heart rate(on 2 study days)