Biomechanics of Optic Neuropathy

Study Overview
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Brief Summary
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The participant is being asked to be a subject in this research study because the participant may have a disorder that can cause optic nerve damage and impairment of his/her visual function which is called optic neuropathies (ON). Optic neuropathy refers to damage to the optic nerve (a cable connecting the eyes and the brain to transmit the visual signals) due to any cause.In this study, the investigator is using magnetic resonance imaging (MRI) and ophthalmic measures such as optic coherent tomography(OCT), which are non-invasive imaging tests to measure the changes in eye globe shape ,the flow of blood and brain fluid. It is hoped that this study will provide new knowledge that may allow the investigator to better understand the cause of symptoms associated with optic neuropathy and ways to better monitor what is happening.

Official Title
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Biomechanics of Optic Neuropathy

Conditions
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Optic Neuropathy

Intervention / Treatment
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* Device: magnetic resonance image (MRI)
* Device: Optical Coherence Tomography (OCT)


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria : 18 years old and on Patients with optic neuropathy(10) and age controlled healthy subjects(10) Exclusion Criteria : For patients: Subjects with history of neurological or ocular disease other than optic neuropathy and refractory error. For healthy control group: History of systemic disease except hypertension. Pregnant women and prisoners will be excluded.

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| control group<br>Healthy participants will receive a one-time assessment of quantitative Magnetic Resonance Imaging (MRI) and spectrum domain optical coherence tomography (OCT). | Device: magnetic resonance image (MRI)<br>* Radiographic imaging that takes about 30-45 minutes<br>Device: Optical Coherence Tomography (OCT)<br>* Images taken from the back of the eye (retina)<br>|
| optic neuropathy group<br>Participants with optic neuropathy will receive a one-time assessment of quantitative Magnetic Resonance Imaging (MRI) and spectrum domain optical coherence tomography (OCT). | Device: magnetic resonance image (MRI)<br>* Radiographic imaging that takes about 30-45 minutes<br>Device: Optical Coherence Tomography (OCT)<br>* Images taken from the back of the eye (retina)<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Globe deformation | Three measures of globe deformation are calculated by using the distance map: 1) optic nerve cupping(ONC), depicting the extent of the nerve head cupping; 2) posterior scleral bowing, depicting the degree of displacement of the posterior wall, and 3) maximal deformation (MD), depicting the combined deformation due to the displacement and the nerve cupping. | day 1 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| intracranial pressure | Intracranial pressure will be measured using non invasive MRI. | Day 1 | 
| Corneal thickness | Corneal thickness will be measured by corneal pachymetry. After anesthetic numbing drop is placed on the eye, blunt probe will briefly touch the participant's eye to obtain the measurement. | Day 1 | 
| Visual field defect | Humphrey Field Analyzer II will be used to acquire the Mean deviation(MD). | Day 1 | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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glaucoma, Leber optic neuropathy, anterior ischemic optic neuropathy