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NCT Number: NCT03760432

Collagen Cross-linking in Keratoconus

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.

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Key information

Conditions

Keratoconus Corneal Diseases Eye Diseases

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Diagnosis of keratoconus
  • Minimum corneal thickness of 410 microns

Exclusion criteria

  • Inability to maintain fixation for OCT imaging
  • Inability to commit to required study visits
  • Inability to give informed consent
  • 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

Treatment and study plan

Laser Custom Corneal Collagen Cross-Linking

Procedure

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.

Primary outcomes

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

    Time frame: 6 months after the CXL procedure

    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.

Secondary outcomes

  1. Determine CXL demarcation line depth

    Time frame: 1 month after the CXL procedure

    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.

Study contacts

Contact information is provided by the study sponsor or research team.

Denzil Romfh, OD

CONTACT

[email protected]

503-494-4351

Humberto Martinez, COT

CONTACT

[email protected]

503-494-7712

Sponsors and collaborators

Lead sponsor

Oregon Health and Science University

Other

Collaborators

  • National Eye Institute (NEI)

Registry information

Official study title

Clinical Trial of Laser Custom Corneal Collagen Cross-Linking in Keratoconus

Important dates

Study start
2018
Primary completion
2026
Study completion
2027
First posted
Nov 30, 2018
Registry last updated
Sep 9, 2025

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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