One-Year Outcomes After Conventional vs Accelerated Epi-Off Corneal Cross-Linking in Progressive Keratoconus (Observational Cohort)

NCT07194538 | Completed

• 1 other identifier: 8.1-25/223-2 02/013 AG
• Study Type: observational
• Target: 20
• Locations: 1 country
• Sites: 1

Brief Summary

Prospective, observational (consecutive eligible eyes) continuation of a previously published 6-month cohort from the same center, extending follow-up to 12 months. Patients with progressive keratoconus received either conventional (CXL30: 3 mW/cm² × 30 min) or accelerated (CXL10: 9 mW/cm² × 10 min) epi-off CXL as part of routine clinical care. Assignment to CXL30 or CXL10 was at the discretion of the treating surgeon; no prospective allocation or randomization was performed. Outcomes included ABCD grading metrics (ABCD-A/B), Kmax, anterior/posterior radii of curvature (ARC/PRC), thinnest pachymetry, and visual acuity at 12 months. The primary objective was to evaluate one-year stabilization/remodeling and compare anterior/posterior responses between protocols.

Conditions

Keratoconus

Keywords

keratoconus; corneal crosslinking; conventional CXL; accelerated CXL; ABCD grading system; one-year outcome; Scheimpflug tomography

Outcome Measures

Primary Outcomes (1)

• Change in ABCD-A from baseline to 12 months

  Belin ABCD parameter A = A stage (ordinal severity stage); Belin ABCD keratoconus grading system (A = anterior corneal radius of curvature at the thinnest point; B = posterior corneal radius of curvature at the thinnest point; C = thinnest corneal pachymetry; D = distance best-corrected visual acuity). minimum value 0, maximum value 4 (ordinal scale 0-4) higher score means worse outcome

  12 months

Secondary Outcomes (5)

• Change in ARC from baseline to 12 months

  12 months

• Change in PRC from baseline to 12 months

  12 months

• Change in Kmax from baseline to 12 months

  12 months

• Change in UDVA and BCVA from baseline to 12 months

  12 months

• Change in thinnest pachymetry from baseline to 12 months

  12 months

Study Arms (2)

Cohort 1 - CXL30 (Conventional)

Conventional Dresden protocol; irradiance 3 mW/cm² for 30 minutes; epi-off; riboflavin 0.1%. Assignment was per treating surgeon's standard-of-care decision (no prospective allocation).

Cohort 2 - CXL10 (Accelerated)

Accelerated protocol; irradiance 9 mW/cm² for 10 minutes; epi-off; riboflavin 0.1%. Assignment was per treating surgeon's standard-of-care decision (no prospective allocation).

Eligibility Criteria

• Sex: all
• Healthy Volunteers: No
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Non-Probability Sample

Study Population

Patients with progressive keratoconus treated at University Hospital Centre Zagreb (Croatia).

You may qualify if:

• Progressive keratoconus documented on serial Scheimpflug tomography within the prior 12 months (ABCD/K-metrics and/or pachymetry).
• Clear corneal axis (no visually significant scarring).
• Corneal thickness 370 μm or more

You may not qualify if:

• No central corneal scars, prior chemical burns, severe corneal infection, or ocular surface disease.
• No pregnancy and lactation during treatment.

Sponsors & Collaborators

• Clinical Hospital Centre Zagreb: lead

Study Sites (1)

University Hospital Centre Zagreb

Zagreb, 10 000, Croatia

Location

MeSH Terms

Conditions

Keratoconus

Condition Hierarchy (Ancestors)

Corneal Diseases; Eye Diseases

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Medical Doctor, Ophtalmology and Optometrist Specialist, FEBO

Study Record Dates

• First Submitted: September 18, 2025
• First Posted: September 26, 2025
• Study Start: May 9, 2021
• Primary Completion: January 12, 2023
• Study Completion: January 12, 2023
• Last Updated: October 1, 2025

Record last verified: 2025-09

Data Sharing

• IPD Sharing: Will not share

Locations

CR (1)