Neurovascular Coupling in Subjects With Amblyopia

Tracking Information
First Submitted Date ICMJE	December 7, 2012
First Posted Date ICMJE	December 11, 2012
Last Update Posted Date	January 9, 2018
Actual Study Start Date ICMJE	March 2014
Estimated Primary Completion Date	January 2019 (Final data collection date for primary outcome measure)
Current Primary Outcome Measures ICMJE; (submitted: December 7, 2012)	Retinal Vessel Diameter in Response to Flickering Light (DVA) [ Time Frame: once on the study day ]
Original Primary Outcome Measures ICMJE	Same as current
Change History	Complete list of historical versions of study NCT01746693 on ClinicalTrials.gov Archive Site
Current Secondary Outcome Measures ICMJE; (submitted: December 7, 2012)	Retinal (arterial and venous) oxygen saturation [ Time Frame: once on the study day ]; Retinal blood velocity in response to flickering light [ Time Frame: once on the study day ]; High resolution functional and anatomical imaging of the visual pathway [ Time Frame: once on the study day ]; Inner Retinal Function [ Time Frame: once on the study day ]
Original Secondary Outcome Measures ICMJE	Same as current
Current Other Outcome Measures ICMJE	Not Provided
Original Other Outcome Measures ICMJE	Not Provided
Descriptive Information
Brief Title ICMJE	Neurovascular Coupling in Subjects With Amblyopia
Official Title ICMJE	Neurovascular Coupling in Subjects With Amblyopia
Brief Summary	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	Not Provided
Study Type ICMJE	Interventional
Study Phase	Not Applicable
Study Design ICMJE	Allocation: Non-Randomized; Intervention Model: Parallel Assignment; Masking: Single (Outcomes Assessor); Primary Purpose: Basic Science
Condition ICMJE	Amblyopia ex Strabismus; Amblyopia ex Anisometropia
Intervention ICMJE	Device: Dynamic Vessel Analyzer retinal vessel diameter, retinal oxygen saturation; Other: Laser Doppler Velocimetry retinal blood flow velocity, retinal blood flow; Device: 7-Tesla MRI High resolution functional and anatomical imaging of the visual pathway; Other: Pattern electroretinography inner retinal function; Other: Fourier domain optical coherence tomography Blood flow in retina.
Study Arms	Experimental: amblyopia ex anisometropia 20 male and female volunteers with amblyopia ex anisometropia Interventions: Device: Dynamic Vessel Analyzer Other: Laser Doppler Velocimetry Device: 7-Tesla MRI Other: Pattern electroretinography Other: Fourier domain optical coherence tomography; Experimental: amblyopia ex strabismus 20 male and female volunteers with amblyopia ex strabismus Interventions: Device: Dynamic Vessel Analyzer Other: Laser Doppler Velocimetry Device: 7-Tesla MRI Other: Pattern electroretinography Other: Fourier domain optical coherence tomography; Experimental: control subjects 20 healthy male and female control subjects Interventions: Device: Dynamic Vessel Analyzer Other: Laser Doppler Velocimetry Device: 7-Tesla MRI Other: Pattern electroretinography Other: Fourier domain optical coherence tomography
Publications *	Not Provided
* Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
Recruitment Information
Recruitment Status ICMJE	Recruiting
Estimated Enrollment ICMJE; (submitted: December 7, 2012)	60
Original Estimated Enrollment ICMJE	Same as current
Estimated Study Completion Date	April 2019
Estimated Primary Completion Date	January 2019 (Final data collection date for primary outcome measure)
Eligibility Criteria ICMJE	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
Sex/Gender	Sexes Eligible for Study: All
Ages	18 Years to 55 Years (Adult)
Accepts Healthy Volunteers	Yes
Contacts ICMJE	Contact: Gerhard Garhoefer, MD +43140400 ext 2981 gerhard.garhoefer@meduniwien.ac.at
Listed Location Countries ICMJE	Austria
Removed Location Countries
Administrative Information
NCT Number ICMJE	NCT01746693
Other Study ID Numbers ICMJE	OPHT-291012
Has Data Monitoring Committee	Yes
U.S. FDA-regulated Product	Not Provided
IPD Sharing Statement	Not Provided
Responsible Party	Gerhard Garhofer, Medical University of Vienna
Study Sponsor ICMJE	Medical University of Vienna
Collaborators ICMJE	Not Provided
Investigators ICMJE	Not Provided
PRS Account	Medical University of Vienna
Verification Date	January 2018
ICMJE Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP