Functional MRI Study of Cortical Modifications to Light Stimulation in Patients With Photophobia

Dry Eye Syndrome Clinical Trial

Official title:

Modification of Cortical Activation After Luminous Stimulation in Functional Magnetic Resonance Imaging (MRI) in Patients With Photophobia Related to Moderate to Acute Dry Eye Syndrome.

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT03464357
• Other study ID #: RC31/17/0275
• Secondary ID: 2017-A02601-52
• Status: Recruiting
• Phase: N/A
• First received: March 7, 2018
• Last updated: April 16, 2018
• Start date: March 13, 2018
• Est. completion date: March 2019

Study information

• Verified date: April 2018
• Source: University Hospital, Toulouse
• Contact: François Malecaze, MD
• Phone: 5 61 77 77 52
• Email: malecaze.fr[@]chu-toulouse.fr
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Photophobia is a common and disabling symptom in patient with dry eye syndrome. The aim of this study is tried to better understand this complain analyzing brain activation during a luminous stimulation to highlight modification of cortical activation.

Description:

Dry eye syndrome is a frequent and underestimated disease whose incidence tends to increase because of the population ageing and behaviors modification (time spent using screens increased, wearing of contact lenses…). Photophobia deteriorates the quality of life in patients with dry eye syndrome decreasing outdoor activities. This symptom is not understood and does not seem to be linked with dry eye syndrome severity. The study will compare cortical activation after luminous stimulation of 16 patients eyes (8 patients with dry eye syndrome and photophobia vs 8 asymptomatic patients) using functional MRI (fMRI).

The primary study endpoint was the extent of magnetic signals in visual cortex after luminous stimulation. Secondary endpoints were the spatial activation extent in the 3 areas of the visual cortex (Brodmann areas 17,18,19).

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 16
• Est. completion date: March 2019
• Est. primary completion date: March 2019
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• Symptomatic subjects : presence of bilateral photophobia with an impact on daily activities (driving, outdoor activities, screens use, socio-professional activities…) in a context of patent dry eye syndrome

• Asymptomatic subjects : no dry eye syndrome and no photophobia

• Patients able to understand medical information and sign consent.

Exclusion Criteria:

• Ophthalmological pathologies of cornea, iris, optic nerve or retina

• MRI contraindications (metallic prosthesis, pacemaker, claustrophobia)

• Neurological pathology which may affect MRI results

• Subjects under legal protection

Related Conditions & MeSH terms

• Dry Eye Syndrome
• Dry Eye Syndromes
• Keratoconjunctivitis Sicca
• Photophobia
• Syndrome

Intervention

Radiation:
• fMRI
The BOLD (Blood-Oxygen-Level Dependent) signal obtained by fMRI reflects the rate of oxygenation of the blood in the brain. However, the hemodynamic response that corresponds to an inflow of oxygenated blood increases in regions that consume energy. Thus, it is possible, by the study of the BOLD signal, to know with a great precision the regions of the brain specially active during a given task. The recorded signals reflect a neuronal activation. For each eye, recordings with and without flash visual stimulation are performed alternately.

Locations

Country	Name	City	State
France	University Hospital Toulouse	Toulouse

Sponsors (1)

Lead Sponsor	Collaborator
University Hospital, Toulouse

Country where clinical trial is conducted

France, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	The spatial extent of activation of the visual cortex	Measurement of voxel activation is validated and standardized (SPM8 software (Wellcome Department of Cognitive Neurology, London, UK) . In order to be able to determine the anatomical location of the voxels, a registration of the images on the standard image MNI152 (Montreal National Institute) provided by the Montreal Neurological Institute for which the spatial location of all the areas is known will be realized. It will thus be obtained, the number of activated voxels per visual area (Brodmann 17, 18, 19) for each hemisphere (contralateral and ipsilateral) of a subject with or without complaint.	One day