Neurovascular Coupling in Subjects With Amblyopia

NCT ID: NCT01746693

Last Updated: 2022-04-07

Study Results

Results pending

The study team has not published outcome measurements, participant flow, or safety data for this trial yet. Check back later for updates.

Basic Information

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Recruitment Status

UNKNOWN

Clinical Phase

NA

Total Enrollment

60 participants

Study Classification

INTERVENTIONAL

Study Start Date

2014-03-31

Study Completion Date

2023-09-02

Brief Summary

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Amblyopia is a developmental condition that is characterized by reduced vision of the eye due to the presence of a sensory impediment during visual development, such as strabismus (ocular misalignment) or anisometropia (unequal refractive error), occurring early in life. Recent studies in humans and animals point towards a cortical locus for the processing deficit in amblyopia, revealing sensory deficits at the signal cell level. If changes in retinal neuronal function are also present, is unknown.

Like in the brain, blood flow in the retina is coupled to neuronal activity. This phenomenon has been measured by different study groups with non invasive techniques in the brain and retina. It has been shown in previous studies that stimulating the retina with diffuse luminant flickering light increases retinal vessel diameter and blood flow. However, it is unknown whether this is also the case in the retina of amblyopic eyes. Additionally, the introduction of blood oxygen level dependent (BOLD) fMRI also makes it possible to directly access the vascular response in the brain to visual stimuli.

Therefore, the aim of the present study is to investigate the effect of luminant flickering light on retinal vessel diameter and retinal blood flow in subjects with amblyopia. Also, oxygen saturation in retinal vessels will be assessed as well as pattern ERG for assessment of retinal function. Additionally, a high resolution image of the visual pathway will be taken with 7 Tesla MRI to investigate whether anatomical or functional alterations are present.

Detailed Description

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Conditions

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Amblyopia ex Strabismus Amblyopia ex Anisometropia

Study Design

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Allocation Method

NON_RANDOMIZED

Intervention Model

PARALLEL

Primary Study Purpose

BASIC_SCIENCE

Blinding Strategy

SINGLE

Outcome Assessors

Study Groups

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amblyopia ex anisometropia

20 male and female volunteers with amblyopia ex anisometropia

Group Type EXPERIMENTAL

Dynamic Vessel Analyzer

Intervention Type DEVICE

retinal vessel diameter, retinal oxygen saturation

Laser Doppler Velocimetry

Intervention Type OTHER

retinal blood flow velocity, retinal blood flow

7-Tesla MRI

Intervention Type DEVICE

High resolution functional and anatomical imaging of the visual pathway

Pattern electroretinography

Intervention Type OTHER

inner retinal function

Fourier domain optical coherence tomography

Intervention Type OTHER

Blood flow in retina.

amblyopia ex strabismus

20 male and female volunteers with amblyopia ex strabismus

Group Type EXPERIMENTAL

Dynamic Vessel Analyzer

Intervention Type DEVICE

retinal vessel diameter, retinal oxygen saturation

Laser Doppler Velocimetry

Intervention Type OTHER

retinal blood flow velocity, retinal blood flow

7-Tesla MRI

Intervention Type DEVICE

High resolution functional and anatomical imaging of the visual pathway

Pattern electroretinography

Intervention Type OTHER

inner retinal function

Fourier domain optical coherence tomography

Intervention Type OTHER

Blood flow in retina.

control subjects

20 healthy male and female control subjects

Group Type EXPERIMENTAL

Dynamic Vessel Analyzer

Intervention Type DEVICE

retinal vessel diameter, retinal oxygen saturation

Laser Doppler Velocimetry

Intervention Type OTHER

retinal blood flow velocity, retinal blood flow

7-Tesla MRI

Intervention Type DEVICE

High resolution functional and anatomical imaging of the visual pathway

Pattern electroretinography

Intervention Type OTHER

inner retinal function

Fourier domain optical coherence tomography

Intervention Type OTHER

Blood flow in retina.

Interventions

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Dynamic Vessel Analyzer

retinal vessel diameter, retinal oxygen saturation

Intervention Type DEVICE

Laser Doppler Velocimetry

retinal blood flow velocity, retinal blood flow

Intervention Type OTHER

7-Tesla MRI

High resolution functional and anatomical imaging of the visual pathway

Intervention Type DEVICE

Pattern electroretinography

inner retinal function

Intervention Type OTHER

Fourier domain optical coherence tomography

Blood flow in retina.

Intervention Type OTHER

Eligibility Criteria

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Inclusion Criteria

* Men and women aged between 18 and 55 years
* Non-smokers (for at least 6 months)
* Normal findings in the medical history and physical examination unless the investigator considers an abnormality to be clinically irrelevant
* Normal ophthalmic findings except amblyopia on one eye resulting from anisometropia or strabismus with a visual acuity of Snellen ≤ 0.3 with best correction on the amblyopic eye and Snellen 0.9 or better in the contralateral eye (for subjects with amblyopia)
* Normal ophthalmic findings with visual acuity of Snellen ≥ 1.0 in both eyes (for control subjects)

Exclusion Criteria

* Symptoms of a clinically relevant illness in the 3 weeks before the first study day
* Presence or history of a severe medical condition as judged by the clinical investigator
* Regular use of medication, abuse of alcoholic beverages, participation in a clinical trial in the 3 weeks preceding the study (except oral contraceptives)
* Blood donation during the previous three weeks
* Pregnancy, planned pregnancy or lactating
* Any metallic, electric, electronic or magnetic device or object not removable except dental fillings
* Claustrophobia
* Epilepsia, history or family history of seizures
Minimum Eligible Age

18 Years

Maximum Eligible Age

55 Years

Eligible Sex

ALL

Accepts Healthy Volunteers

Yes

Sponsors

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Medical University of Vienna

OTHER

Sponsor Role lead

Responsible Party

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Gerhard Garhofer

Assoc. Prof. PD Dr.

Responsibility Role PRINCIPAL_INVESTIGATOR

Locations

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Department of Clinical Pharmacology, Medical University of Vienna

Vienna, , Austria

Site Status RECRUITING

Countries

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Austria

Central Contacts

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Gerhard Garhoefer, MD

Role: CONTACT

+43140400 ext. 2981

Facility Contacts

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Gerhard Garhoefer, MD

Role: primary

+43140400 ext. 2981

Other Identifiers

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OPHT-291012

Identifier Type: -

Identifier Source: org_study_id

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