An observational study in Pain, Postoperative, Pain, Chronic and Pain, Acute, sponsored by Boston Children's Hospital. Recruiting at 1 site in United States. Open to participants aged 8 Years to 35 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2025-12-19.
Sponsored by Boston Children's Hospital · Observational
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).
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.
5,640 studies on the registry are indexed under Pain, Postoperative; 1,230 are open to participants now.
This study's planned enrollment of 60 is below the median of 102 across 683 observational studies indexed under Pain, Postoperative.
Browse Pain, Postoperative studies →Boston Children's Hospital is the lead sponsor of 608 studies on the registry; 147 are open to participants now.
Of its 32 completed or terminated interventional studies of FDA-regulated products, 19 (59%) have results posted.
Counted across the registry records on this site, refreshed daily.
The population under study are patients with keratoconus who are undergoing a corneal cross-linking (CXL) procedure. Keratoconus is an eye condition where the cornea progressively develops abnormally into a cone shape, which can lead to distorted vision and irreversible vision loss The CXL procedure is designed to restore and maintain the shape of the cornea to avoid these complications.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
CXL Group
Control Group
Exclusion Criteria (Both Groups):
Current axis I psychiatric disorders. Chronic pain Significant head injury Seizures Brain tumor Cerebrovascular accident Neurological disease aside from migraine -AIDs Prescription medication strongly implicated in causing dry eyes
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
DSM diagnostic criteria
The American Psychiatric Association’s manual of mental health diagnoses. DSM-5 (2013, revised as DSM-5-TR in 2022) replaced DSM-IV, and some studies still name the older edition. “Meets DSM criteria for …” means diagnosed by that edition’s diagnostic criteria, usually by a clinician in an interview.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
HIV
The human immunodeficiency virus, which weakens the immune system.
Many studies now accept people whose HIV is controlled on treatment, judged by the viral load and the CD4 count. Check the limits this study sets.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Patients who are about to undergo a corneal cross-linking (CXL) surgery to treat keratoconus.
Healthy volunteers age and sex matched to the CXL group.
Neural activity related to pain.
Pain-related brain activation measured with fMRI.
Time frame: 1 year
Corneal nerve morphology.
Afferent nerve fiber morphology measured with IVCM.
Time frame: 1 year
Plan to share: Yes — All IPD that underlie results in a publication
Supporting information: Study protocol, Statistical analysis plan, Informed consent form, Clinical study report, Analytic code
Time frame: Starting 6 months after publication, until 5 years after.
Access criteria: Direct request to study personnel via email, letter, phone, or in-person communication. Information will be shared with requesting parties for the purposes of expanding on this research or re-analysis. Neuroimaging data and corneal microscopy data will be shared via secure digital electronic transfer.
Started Oct 2021 (actual). Primary completion is estimated for Aug 2027, 70 months after the start.
Of 391 non-industry observational studies under Pain, Postoperative, half reached primary completion within 13 months of starting (the median), counting those still running; a quarter within 5 and three quarters within 32. This study's planned 70 months is above that.
Counting every sponsor, half of 395 studies reached it within 13 months; a quarter within 5 and three quarters within 33.
How these figures are worked out, and which studies are left out of them.
Eligibility is decided by the study team. Share this record with your doctor or contact the team directly.
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