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Recruiting NCT04439552

fMRI and IVCM Cornea Microscopy of CXL in Keratoconus

— Observational Pain, Postoperative Pain, Chronic Pain, Acute Surgical Injury

For patients and families

In plain language

An automatic summary of structured registry data. It is an orientation aid, not a substitute for the official protocol or a physician assessment.

What is being studied
This is an observational study: the protocol does not assign a study treatment.
Who it may be relevant to
Registry conditions: Pain, Postoperative, Pain, Chronic, Pain, Acute, Surgical Injury. Basic parameters: 8 years — 35 years · All.
What needs checking
Age, condition and sex are only basic indicators. Prior treatment, laboratory values and other mandatory requirements appear in the eligibility criteria below.
Where it takes place
United States
Next step
Save the trial, show it to the treating physician, and confirm current recruitment with the study center. Costs, documents and travel →

Unsure about the terms? Read our patient guide →

Official title

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

Overview

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

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.

Primary outcome measures

  • Neural activity related to pain. [Time frame: 1 year]
  • Corneal nerve morphology. [Time frame: 1 year]

Eligibility criteria

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

Criteria are shown verbatim from the registry (in English). Final eligibility is always assessed by the study center.

Healthy volunteers: Yes

Study design

Observational model
Cohort

Study locations

United States · 1 center
  • Boston Children's Hospital — Boston

Publications

  • Belmonte C, Acosta MC, Merayo-Lloves J, Gallar J. What Causes Eye Pain? Curr Ophthalmol Rep. 2015;3(2):111-121. doi: 10.1007/s40135-015-0073-9. PMID 26000205
  • Borsook D, Youssef AM, Simons L, Elman I, Eccleston C. When pain gets stuck: the evolution of pain chronification and treatment resistance. Pain. 2018 Dec;159(12):2421-2436. doi: 10.1097/j.pain.0000000000001401. PMID 30234696
  • Cruzat A, Qazi Y, Hamrah P. In Vivo Confocal Microscopy of Corneal Nerves in Health and Disease. Ocul Surf. 2017 Jan;15(1):15-47. doi: 10.1016/j.jtos.2016.09.004. Epub 2016 Oct 19. PMID 27771327
  • Downie LE, Naranjo Golborne C, Chen M, Ho N, Hoac C, Liyanapathirana D, Luo C, Wu RB, Chinnery HR. Recovery of the sub-basal nerve plexus and superficial nerve terminals after corneal epithelial injury in mice. Exp Eye Res. 2018 Jun;171:92-100. doi: 10.1016/j.exer.2018.03.012. Epub 2018 Mar 14. PMID 29550279
  • Ghanem VC, Ghanem RC, de Oliveira R. Postoperative pain after corneal collagen cross-linking. Cornea. 2013 Jan;32(1):20-4. doi: 10.1097/ICO.0b013e31824d6fe3. PMID 22547128
  • Hruschak V, Cochran G. Psychosocial predictors in the transition from acute to chronic pain: a systematic review. Psychol Health Med. 2018 Dec;23(10):1151-1167. doi: 10.1080/13548506.2018.1446097. Epub 2018 Feb 28. PMID 29490476
  • Hasenbring MI, Chehadi O, Titze C, Kreddig N. Fear and anxiety in the transition from acute to chronic pain: there is evidence for endurance besides avoidance. Pain Manag. 2014;4(5):363-74. doi: 10.2217/pmt.14.36. PMID 25350076
  • Kehlet H, Jensen TS, Woolf CJ. Persistent postsurgical pain: risk factors and prevention. Lancet. 2006 May 13;367(9522):1618-25. doi: 10.1016/S0140-6736(06)68700-X. PMID 16698416

Identifiers

NCT: NCT04439552 · IRB-P00035185

Primary sources (government registries)

View this study on ClinicalTrials.gov ↗