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

NCT ID: NCT03464357

Last Updated: 2018-04-18

Basic Information

• Recruitment Status: UNKNOWN
• Clinical Phase: NA
• Total Enrollment: 16 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2018-03-13
• Study Completion Date: 2019-03-31

Brief 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.

Detailed 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).

Conditions

Dry Eye Syndrome; Photophobia

Study Design

• Allocation Method: NON_RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: OTHER
• Blinding Strategy: NONE

Study Groups

Symptomatic patients with dry eye

8 symptomatic patients with dry eye (mild to severe) assessed using a validated questionnaire (OSDI score, Appendix 1) associated with a disabling photophobia (need to wear sunglasses permanently outside, restriction of the outputs in case of significant brightness, restriction of the use of the screens because of the visual embarrassment ...). The fMRI will be carried out following the inclusion visit after all the necessary checks

Group Type: ACTIVE_COMPARATOR

fMRI

Intervention Type: RADIATION

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.

Asymptomatic patient

8 asymptomatic patients presenting neither photophobia (even minimal) or dry eye.

The fMRI will be carried out following the inclusion visit after all the necessary checks

Group Type: ACTIVE_COMPARATOR

fMRI

Intervention Type: RADIATION

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.

Interventions

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.

Intervention Type: RADIATION

Eligibility Criteria

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

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

University Hospital, Toulouse

OTHER

Sponsor Role: lead

Responsible Party

Responsibility Role: SPONSOR

Principal Investigators

François Malecaze, MD

Role: PRINCIPAL_INVESTIGATOR

University Hospital, Toulouse

Locations

University Hospital Toulouse

Toulouse, , France

Site Status: RECRUITING

Countries

France

Central Contacts

François Malecaze, MD

Role: CONTACT

malecaze.fr@chu-toulouse.fr

5 61 77 77 52 ext. 33

Isabelle Olivier, PhD

Role: CONTACT

olivier.i@chu-toulouse.fr

5 61 77 70 51 ext. 33

Facility Contacts

François Malecaze, MD

Role: primary

malecaze.fr@chu-toulouse.fr

5 61 77 77 52 ext. 33

Isabelle Olivier, PhD

Role: backup

olivier.i@chu-toulouse.fr

5 61 77 70 51 ext. 33

Other Identifiers

2017-A02601-52

Identifier Type: OTHER

Identifier Source: secondary_id

RC31/17/0275

Identifier Type: -

Identifier Source: org_study_id