fMRI and IVCM Cornea Microscopy of CXL in Keratoconus

Study Overview
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Brief Summary
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Evaluation of neuroplasticity of pain pathways and corneal afferent nerve regeneration following corneal crosslinking (CXL) in keratoconus patients using fMRI and corneal In Vivo Confocal Microscopy (IVCM).

Detailed Description
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Our long-term goal is to evaluate the transition from acute to chronic pain that sometimes occurs following CXL in keratoconus patients. This study will determine whether these changes can be structurally and functionally quantified using functional neuroimaging and in vivo corneal microscopy (IVCM), and whether they can be predicted based on predisposing biological and psychological factors. Our central hypothesis is that CXL produces acute pain through activation of trigeminal afferents, and that post-operative chronic pain outcomes are related to neuroplastic changes in trigeminal circuitry, corneal afferent regeneration, and psychological factors.

Official Title
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Neuroplasticity of Pain Pathways and Corneal Afferent Regeneration Following Corneal Crosslinking (CXL) in Keratoconus

Conditions
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Pain, Postoperative, Pain, Chronic, Pain, Acute, Surgical Injury, Surgical Wound, Cornea Injury, Cornea, Keratoconus

Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: CXL Group Age 8-35 years Clinical diagnosis of keratoconus and seeking CXL treatment English speaking ability sufficient to comprehend consent with parental assistance MRI compatible Ability to lie still for an MRI session (60 minutes) Control Group Age 8-35 years No diagnosis of keratoconus English speaking ability sufficient to comprehend consent with parental assistance MRI compatible Ability to lie still for an MRI session (60 minutes) Exclusion Criteria (Both Groups): Claustrophobic Weight > 285 lbs (weight limit of the MRI table) Significant medical history, including: Current DSM-IV-TR axis I psychiatric disorders. Chronic pain Significant head injury Seizures Brain tumor Cerebrovascular accident Neurological disease aside from migraine HIV-AIDs Prescription medication strongly implicated in causing dry eyes Magnetic implants or metal-containing tattoos on their chest or above Pregnancy History of contact lens wear Any allergic response to a numbing eyedrop in the past

Ages Eligible for Study
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Minimum Age: 8 Years
Maximum Age: 35 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 |
| --- | --- |
| CXL group<br>Patients who are about to undergo a corneal cross-linking (CXL) surgery to treat keratoconus. | |
| Control group<br>Healthy volunteers age and sex matched to the CXL group. | |

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Neural activity related to pain. | Pain-related brain activation measured with fMRI. | 1 year | 
| Corneal nerve morphology. | Afferent nerve fiber morphology measured with IVCM. | 1 year | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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fMRI, Corneal Microscopy, IVCM, Neuroimaging