Clinical trial NCT04094285: The Effect of Hyperoxia and Hypoxia on Fluorescence Lifetime Imaging Ophthalmoscopy in Healthy Subjects- a Randomized, Double Blind, Crossover Study
Official title: The Effect of Hyperoxia and Hypoxia on Fluorescence Lifetime Imaging Ophthalmoscopy in Healthy Subjects- a Randomized, Double Blind, Crossover Study
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE2
Conditions: To Investigate the Effect of 100% Oxygen Breathing on Fluorescence Lifetime Imaging Ophthalmoscopy (FLIO) in Healthy Subjects
Lead sponsor: Medical University of Vienna
Sponsor class: OTHER
First posted: 2019-09-18
Enrollment: 48
Sex: ALL
Minimum age (years): 18
Maximum age (years): 35
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: The present study aims to investigate whether FLIO can also detect shorttime changes in retinal metabolism induced by hyperoxia and hypoxia. For this purpose, 48 healthy subjects will be included in the present study and changes in FLIO will be assessed during breathing of 100% oxygen to induce hyperoxia as well as during breathing of 12% oxygen in nitrogen to induce hypoxia. Since stimulation with flickering light also induces a higher metabolic demand in the retina (functional hyperemia), thisprovocation test will also applied during breathing of the different gas mixtures and compared to baseline. To gain information about retinal blood flow, optical coherence tomography angiography (OCT-A) will be performed. The results of the present study can help to gain more insight into the physiology of the retinal metabolism and might give grounds to establish new biomarkers in future studies.


Eligibility criteria: Inclusion Criteria:

* Men and women aged between 18 and 35 years

  * Normal ophthalmic findings
  * Ametropia ≤ 6 diopters
  * Normal findings in the medical history and physical examination including ECG unless the investigator considers an abnormality to be clinically irrelevant
  * Nonsmokers

Exclusion Criteria:

Regular use of medication, abuse of alcoholic beverages or drugs

* Participation in a clinical trial in the 3 weeks preceding the study
* Treatment in the previous 3 weeks with any drug (except contraceptives)
* Symptoms of a clinically relevant illness in the 3 weeks before the first study day
* Blood donation during the previous 3 weeks
* History or family history of epilepsy
* Pregnant or breast-feeding women
* Women of childbearing potential (neither menopausal, nor hysterectomized, nor sterilized) not using effective contraception

Primary outcomes:
measure: Changes in FLIO induced by hyperoxia
timeFrame: 15 minutes
Secondary outcomes:
measure: Changes in FLIO induced by hypoxia
timeFrame: 15 minutes
measure: Changes in FLIO induced by flicker stimulation
timeFrame: 15 minutes
measure: Changes in OCT-A induced by hyperoxia
timeFrame: 15 minutes
measure: Changes in OCT-A induced by hypoxia
timeFrame: 15 minutes
measure: Changes in OCT-A induced by flicker stimulation
timeFrame: 15 minutes
measure: Retinal oxygen saturation
timeFrame: 15 minutes
measure: Retinal vessel diameter
timeFrame: 15 minutes
measure: Changes in peripheral oxygen saturation
timeFrame: 15 minutes
measure: Changes in blood gas parameters (pH, pCO2, PO2 and SaO2)
timeFrame: 15 minutes
Other outcomes:
Locations:
city: Vienna
country: Austria
facility: Department of Clinical Pharmacology, Medical University of Vienna, Austria
Study officials:
References: