ClinicalTrials.gg
RecruitingNCT03760432Updated Sep 9, 2025

Collagen Cross-linking in Keratoconus

An interventional study of Laser Custom Corneal Collagen Cross-Linking in Keratoconus, sponsored by Oregon Health and Science University. Recruiting at 1 site in United States. Open to participants aged 18 Years and older. Per ClinicalTrials.gov, last updated 2025-09-09.

Sponsored by Oregon Health and Science University · Not applicable, Interventional, and Treatment

From the registry’s dates

  • Registered 5 months after the study started (first participant enrolled Jun 2018, registered Nov 2018).
  • Started Jun 2018; still recruiting 8 years 4 months later.
Phase
Not applicable
Study type
Interventional
Enrollment
100
Allocation
Not applicable
Ages
18 Years and older
Sex
All
01

Study summary

Optical Coherence Tomography (OCT) devices are non-contact instruments that can measure the depth of scars, other causes of cloudiness of the cornea, and degree of corneal thinning in patients with keratoconus. Laser Custom Corneal Collagen Cross-linking (CXL) significantly decreases corneal aberrations and improves vision. This study will use OCT-guided setting for the lasers used in the corneal smoothing portion of the laser custom CXL procedure to assess the affect on visual outcomes.

Read the detailed description

In the U.S., CXL and topography-guided laser ablation were approved independently, but not together. Another variation in technique involves the use of mitomycin-C (MMC), which is effective in reducing corneal haze after the laser surface ablation. Use of MMC during the laser custom CXL was associated with better outcomes, but in separate trials that could not be directly compared. This study will use OCT measurements to evaluate the magnitudes of direct and indirect laser actions after the procedure.

02

Conditions studied

  • Keratoconus

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Keywords

  • Keratoconus (KCN)
  • Optical Coherence Tomography (OCT)
  • Collagen Cross-linking (CXL)
03

In context

Keratoconus

313 studies on the registry are indexed under Keratoconus; 56 are open to participants now.

This study's planned enrollment of 100 is above the median of 40 across 205 interventional studies indexed under Keratoconus.

Browse Keratoconus studies →

Lead sponsor

Oregon Health and Science University is the lead sponsor of 696 studies on the registry; 131 are open to participants now.

Of its 52 completed or terminated interventional studies of FDA-regulated products, 39 (75%) have results posted.

Counted across the registry records on this site, refreshed daily.

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Who can participate

Ages eligible
18 Years and older
Sexes eligible
All
Accepts healthy volunteers
No

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.

Inclusion criteria

  • Diagnosis of keratoconus
  • Minimum corneal thickness of 410 microns

Exclusion criteria

Exclusion Criteria:

  • Inability to maintain fixation for OCT imaging
  • Inability to commit to required study visits
  • Inability to give
  • Eyes with concurrent retinal diseases, glaucoma, or other eye conditions that may limit the visual outcome after surgery
  • Mature cataracts if found to limit visual potential to worse than 20/40
Terms in these criteria, in plain language(1)

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.

Informed consent

Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.

You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.

05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Not applicable
Intervention model
Single group
Masking
None (open label)
Enrollment
100 participants (estimated)

Study arms

  • Experimental
    Surgery

    OCT-guided custom laser CXL

    Procedure: Laser Custom Corneal Collagen Cross-Linking

Interventions

  • ProcedureLaser Custom Corneal Collagen Cross-Linking

    Preoperative measurements from the OCT are used to assist the calculation in deciding the laser depth settings for smoothing the anterior corneal surface and removing any present opacities. The surgeon uses the OCT data to plan treatment parameters while preserving at least 360 microns of residual corneal stroma using a phototherapeutic keratectomy procedure. After the laser procedure, adjunctive MMC or saline solution will be applied to the cornea in accordance with the group to which the treated eye is randomized. The CXL procedure is then performed following the FDA-approved CXL regimen by Avedro, Inc.

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What researchers measure

Primary outcomes

  1. Improvement in best spectacle-corrected visual acuity after laser custom CXL

    The primary goal of the trial is to determine the extent of visual improvement after laser custom CXL compared to preoperative measurements. Vision will be checked at various time points, but the primary time point will be 6-months post-procedure.

    Time frame: 6 months after the CXL procedure

Secondary outcomes

  1. Determine CXL demarcation line depth

    The study will use OCT imaging to measure the CXL demarcation line inside the entire optical zone. The demarcation line indicates the portion of corneal stroma being cross-linked. This helps determine to what extent the cornea is being strengthened.

    Time frame: 1 month after the CXL procedure

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Study locations

1 of 1 sites recruiting
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Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Sep 9, 2025, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
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Registry details

Key details

Study ID
NCT03760432
Responsible party
David Huang (Peterson Professor of Ophthalmology & Professor of Biomedical Engineering, Oregon Health and Science University) — Principal investigator
First posted
Nov 30, 2018
Start date
Jun 20, 2018
Primary completion
Dec 2026 (estimated)
Completion
Dec 2027 (estimated)
Last update
Sep 9, 2025

Study contacts

Denzil Romfh, OD
Contact
romfhd@ohsu.edu
503-494-4351
Humberto Martinez, COT
Contact
martinhu@ohsu.edu
503-494-7712
David Huang, MD, PhD
principal investigator · Oregon Health and Science University

Oversight

Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

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