Retinal circulation during gravitation changes in a human centrifuge
- Conditions
- Changes in retinal vessel width (veins and arteries) under different gravity conditions
- Registration Number
- DRKS00034414
- Lead Sponsor
- Deutsches Zentrum für Luft- und Raumfahrt - Institut für Luft- und Raumfahrtmedizin
- Brief Summary
Not available
- Detailed Description
Not available
Recruitment & Eligibility
- Status
- Pending
- Sex
- All
- Target Recruitment
- 10
? Male and female healthy subjects aged between 18 and 50 years and a
height of 170-200 cm
? BMI < 30
? Subjects who are willing and able to participate in the entire study
? Successful completion of the inclusion examination or presentation of a
valid SAHC medical
? Present, signed declaration of consent before the start of the first study-
related examination
? All other chronic (infectious) diseases (e.g. anemia,
renal insufficiency, chronic obstructive pulmonary disease, asthma,
diabetes, rheumatism, HIV, hepatitis, varicosis, hypertension > 140
mmHg
systolic or > 90 mmHg diastolic**, etc.)*, **
? Acute (or chronic) disc damage (protrusion / prolapse)
with neurological symptoms and/or pain symptoms
? Neurological/psychiatric diseases (e.g. stroke,
epilepsy, depression)
? Cardiac diseases requiring treatment (e.g. myocardial infarction,
coronary heart disease, stents in place (time of implantation
<12 months or implantation due to acute heart damage),
moderate heart valve insufficiency based on the current
ESC guidelines*, persistent or intermittent atrial fibrillation
atrial fibrillation)***
? Hormonal dysfunctions (in particular diseases of the adrenal glands
adrenal glands, diabetes mellitus, etc.)
? Medication intake (except vitamin D, L-thyroxine* and
anticontraceptives)
? pronounced orthostatic intolerance
? Tendency to kinetosis with nausea and vomiting
? Myopia (short-sightedness) > -6 dpt
? Laser eye surgery
? Acute injuries to the musculoskeletal system
? Abusive substance use (alcohol, other drugs)
? Current or past tendency to bleed or coagulation disorder
coagulation disorder
? Exclusion criteria resulting from the medical inclusion examination
exclusion criteria (e.g. indications of an existing heart
heart disease in the ergometry or in the case of previously unknown
narrow-angle glaucoma)
? Known allergic reactions to atropine derivatives
* except for chronic, stable thyroid diseases (e.g. hypothyroidism) with normal TSH, which are supplemented with L-thyroxine
** Brunström, M., et al. 2023 ESH Guidelines for the management of arterial hypertension The Task Force for the management of arterial hypertension of the European Society of Hypertension. Endorsed by the International Society of Hypertension (ISH) and the European Renal Association (ERA). J Hypertension 41 (2023).
***Baumgartner, Helmut, et al. 2017 ESC/EACTS Guidelines for the management of valvular heart disease. European heart journal 38.36 (2017): 2739-2786.
Study & Design
- Study Type
- interventional
- Study Design
- Not specified
- Primary Outcome Measures
Name Time Method The primary endpoint of the study is the measurement of venous retinal vessel width under +Gz and -Gz conditions on a human centrifuge using a Digital Vessel Analyzer. <br>Based on previous parabolic flight experiments, we expect deviations of more than 13 µm from the normal values of 148 µm +/- 10 µm.
- Secondary Outcome Measures
Name Time Method - Measurement of the arterial retinal vessel width (DVA) and intraocular pressure using a tonometer.<br>- Measurement of the venous volume load using ultrasound examination of the jugular vein.<br>- Measurement of serological inflammatory parameters associated with retinal venous regulation.<br>- Cerebral blood flow velocity (CBFV) of the right middle cerebral artery (MCA) by transcranial ultrasound.<br>- Assessment of macrocirculation and fluid shifts using thoracic impedance, finger blood pressure sensor and ECG systems.