Collagen Cross-linking in Keratoconus

Clinical Trial of Laser Custom Corneal 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.

Study Overview

• Status: Recruiting
• Conditions: Keratoconus
• Intervention / Treatment: Procedure: Laser Custom Corneal Collagen Cross-Linking

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.

• Study Type: Interventional
• Enrollment (Estimated): 100
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Humberto Martinez, COT; Phone Number: 503-494-7712; Email: martinhu@ohsu.edu
• Study Contact Backup: Name: Denzil Romfh, OD; Phone Number: 503-494-4351; Email: romfhd@ohsu.edu

Study Locations

• United States
  • Oregon
    • Portland, Oregon, United States, 97239
      • Recruiting
      • Oregon Health & Science University
      • Contact: Humberto Martinez, COT; Phone Number: 503-494-7712; Email: martinhu@ohsu.edu
      • Contact: Denzil Romfh, OD; Phone Number: 503-494-4351; Email: romfhd@ohsu.edu

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (Adult, Older Adult)
• Accepts Healthy Volunteers: No

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: Surgery; OCT-guided custom laser CXL

Procedure: Laser 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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	6 months after the CXL procedure

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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.	1 month after the CXL procedure

Collaborators and Investigators

• Sponsor: Oregon Health and Science University
• Collaborators: National Eye Institute (NEI)
• Investigators: Principal Investigator: David Huang, MD, PhD, Oregon Health and Science University

Study record dates

Study Major Dates

• Study Start (Actual): June 20, 2018
• Primary Completion (Estimated): December 1, 2025
• Study Completion (Estimated): December 1, 2025

Study Registration Dates

• First Submitted: November 28, 2018
• First Submitted That Met QC Criteria: November 29, 2018
• First Posted (Actual): November 30, 2018

Study Record Updates

• Last Update Posted (Actual): February 12, 2024
• Last Update Submitted That Met QC Criteria: February 8, 2024
• Last Verified: February 1, 2024

More Information

Terms related to this study

• Keywords: Optical Coherence Tomography (OCT); Keratoconus (KCN); Collagen Cross-linking (CXL)
• Additional Relevant MeSH Terms: Eye Diseases; Corneal Diseases; Keratoconus
• Other Study ID Numbers: 6612-CXL; R01EY028755 (U.S. NIH Grant/Contract)

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No