Neurovascular Coupling in Subjects With Amblyopia

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.

Conditions

• Amblyopia ex Strabismus
• Amblyopia ex Anisometropia

Interventions

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.

Sponsors & Collaborators

• Medical University of Vienna

  lead OTHER

Study Design

Allocation

NON_RANDOMIZED

Purpose

BASIC_SCIENCE

Masking

SINGLE

Model

PARALLEL

Eligibility

Min Age

18 Years

Max Age

55 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2014-03-31

Primary Completion

2023-09-30

Completion

2023-09-02

Countries

• Austria

Study Locations