Clinical Trial: Neurovascular Coupling in Subjects With Amblyopia

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: 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 Summary:
Sponsor: Medical University of Vienna

Current Primary Outcome: Retinal Vessel Diameter in Response to Flickering Light (DVA) [ Time Frame: once on the study day ]

Original Primary Outcome: Same as current

Current Secondary Outcome:

  • 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: Same as current

Information By: Medical University of Vienna

Dates:
Date Received: December 7, 2012
Date Started: February 2014
Date Completion: December 2017
Last Updated: November 29, 2016
Last Verified: November 2016