Regulation of Optic Nerve Head Blood Flow During Combined Changes in Intraocular Pressure and Arterial Blood Pressure
Autoregulation is defined as the ability of a vascular bed to adapt its vascular resistance to changes in perfusion pressure. In the eye, several studies have reported that retinal blood flow is autoregulated over a wide range of ocular perfusion pressures. In the optic nerve head only few data are available. Large scale studies have shown that reduced ocular perfusion pressure is an important risk factor for the prevalence, the incidence and the progression of primary open angle glaucoma.
Former studies that investigated ocular blood flow autoregulation only measured choroidal blood flow. For the optic nerve head only few data are available, although it seems likely that it underlies similar autoregulatory mechanisms.
The primary goal of the present study is to gain more insight into these phenomena in humans.
The present study aims to investigate the pressure/flow relationship as a measure for optic nerve head autoregulation during combined changes of intraocular pressure and arterial pressure. Intraocular pressure will be increased by the use of a suction cup technique, mean arterial pressure will be increased by squatting. During the whole procedure, optic nerve head blood flow will be measured continuously.
Studieöversikt
Status
Betingelser
Intervention / Behandling
Studietyp
Inskrivning (Faktisk)
Fas
- Inte tillämpbar
Kontakter och platser
Studieorter
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Vienna, Österrike, 1090
- Department of Clinical Pharmacology, Medical University of Vienna
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Deltagandekriterier
Urvalskriterier
Åldrar som är berättigade till studier
Tar emot friska volontärer
Kön som är behöriga för studier
Beskrivning
Inclusion Criteria:
- Men and women aged between 18 and 35 years, nonsmokers
- Men and women will be included in equal parts
- Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
- Normal findings in the laboratory testings unless the investigator considers an abnormality to be clinically irrelevant
- Normal ophthalmic findings, ametropia less than 1 diopter
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 (except oral contraceptives)
- Symptoms of a clinically relevant illness in the 3 weeks before the first study day
- Blood donation during the previous 3 weeks
Studieplan
Hur är studien utformad?
Designdetaljer
- Primärt syfte: Grundläggande vetenskap
- Tilldelning: N/A
- Interventionsmodell: Enskild gruppuppgift
- Maskning: Ingen (Open Label)
Vapen och interventioner
Deltagargrupp / Arm |
Intervention / Behandling |
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Experimentell: Frisk volontär
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intraokulära tryckmätningar
blodflödesmätningar vid den temporala neuroretinala kanten för att bedöma blodflödet i synnervens huvud
Subjects will perform squatting for 6 minutes while either blood flow or intraocular pressure measurements
Experimental stepwise increase of intraocular pressure while either optic nerve head blood flow or intraocular pressure measurements
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Vad mäter studien?
Primära resultatmått
Resultatmått |
Tidsram |
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Optic nerve head pressure-flow relationship
Tidsram: in total 3x on 2 study days
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in total 3x on 2 study days
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Samarbetspartners och utredare
Sponsor
Studieavstämningsdatum
Studera stora datum
Studiestart
Primärt slutförande (Faktisk)
Avslutad studie (Faktisk)
Studieregistreringsdatum
Först inskickad
Först inskickad som uppfyllde QC-kriterierna
Första postat (Uppskatta)
Uppdateringar av studier
Senaste uppdatering publicerad (Uppskatta)
Senaste inskickade uppdateringen som uppfyllde QC-kriterierna
Senast verifierad
Mer information
Termer relaterade till denna studie
Nyckelord
Andra studie-ID-nummer
- OPHT-150808
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