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.
Studieoversikt
Status
Forhold
Intervensjon / Behandling
Studietype
Registrering (Faktiske)
Fase
- Ikke aktuelt
Kontakter og plasseringer
Studiesteder
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Vienna, Østerrike, 1090
- Department of Clinical Pharmacology, Medical University of Vienna
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Deltakelseskriterier
Kvalifikasjonskriterier
Alder som er kvalifisert for studier
Tar imot friske frivillige
Kjønn som er kvalifisert for studier
Beskrivelse
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
Hvordan er studiet utformet?
Designdetaljer
- Primært formål: Grunnvitenskap
- Tildeling: N/A
- Intervensjonsmodell: Enkeltgruppeoppdrag
- Masking: Ingen (Open Label)
Våpen og intervensjoner
Deltakergruppe / Arm |
Intervensjon / Behandling |
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Eksperimentell: Frivillig frisk
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intraokulære trykkmålinger
blodstrømsmålinger ved den temporale neuroretinale kanten for å vurdere blodstrømmen til synsnerven
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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Hva måler studien?
Primære resultatmål
Resultatmål |
Tidsramme |
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Optic nerve head pressure-flow relationship
Tidsramme: in total 3x on 2 study days
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in total 3x on 2 study days
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Samarbeidspartnere og etterforskere
Sponsor
Studierekorddatoer
Studer hoveddatoer
Studiestart
Primær fullføring (Faktiske)
Studiet fullført (Faktiske)
Datoer for studieregistrering
Først innsendt
Først innsendt som oppfylte QC-kriteriene
Først lagt ut (Anslag)
Oppdateringer av studieposter
Sist oppdatering lagt ut (Anslag)
Siste oppdatering sendt inn som oppfylte QC-kriteriene
Sist bekreftet
Mer informasjon
Begreper knyttet til denne studien
Andre studie-ID-numre
- OPHT-150808
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