German Corneal Cross Linking Register

Corneal Cross Linking is new treatment modality for patients with keratoconus. A keratoconus is characterized by progressive bulging and thinning of the eye's cornea. Keratoconus is a potentially severely sight impairing condition that may necessitate corneal transplantation in the progressive state.

Corneal Cross Linking is designed to

• increase the cornea's mechanical stability
• to stop progression of bulging and thinning of the cornea
• to prevent the need for corneal transplantation

Corneal Cross Linking is performed by

1. Applying Riboflavin (Vitamin B2) eye drops every 2 minutes for 30 minutes to the cornea
2. Illuminating the cornea with UV-light

This register of Corneal Cross Linking procedures performed in Germany serves to

• gather long-term results
• detect rare complications and side-effects
• evaluate the efficacy in a large number of patients

Study Overview

• Status: Active, not recruiting
• Conditions: Keratoconus
• Intervention / Treatment: Procedure: CCL (Corneal Cross Linking)

• Study Type: Observational
• Enrollment (Actual): 356

Contacts and Locations

Study Locations

• Germany
  • Homburg, Germany, 66421
    • University of Saar
  • Münster, Germany, 48145
    • Augenklinik am St. Franziskus Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Child; Adult; Older Adult
• Accepts Healthy Volunteers: No

• Sampling Method: Probability Sample

Study Population

Patients treated with Corneal Cross Linking in Germany

Description

Inclusion Criteria:

• Patients diagnosed with keratokonus and treated with corneal cross Linking in Germany

Exclusion Criteria:

• Non-ectatic conditions

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
1; Cross linked eyes	Procedure: CCL (Corneal Cross Linking); Apply Riboflavin 0.1% in Dextran 500 20% in NaCl solution Illuminate with UV-light of 365 nm wave-length and 3.0 mW/cm² intensity at 5 cm distance; Other Names: CCL; Collagen cross linking; Corneal collagen cross linking; 3C-L

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Visual Acuity	Corrected Visual Acuity after crosslinking at the latest follow up examination	172 to 3396 days
Postoperative K Max	K max after Crosslinking	172 to 3396 days
Sphere	Sphere values after crosslinking at lastest-follow-up	172 to 3396 days
Cylinder	Refractive cylinder after Crosslinking at latest follow-up	172 to 3396 days

Secondary Outcome Measures

Outcome Measure	Time Frame
Slit-lamp biomicroscopical findings	yearly
Best corrected Visual Acuity	Yearly

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Endothelial Cell Density	Endothelial cell density after Crosslinking at latest follow-up	172 to 3396 days

Collaborators and Investigators

• Sponsor: Suphi Taneri
• Investigators: Study Chair: Suphi Taneri, MD, Augenklinik am St. Franziskus Hospital; Study Director: Berthold Seitz, MD, University of Homburg, Saar, Germany; Study Director: Philip Maier, MD, Univer. Freiburg, Germany; Study Director: Claus Cursiefen, MD, Univer. Erlangen, Germany; Principal Investigator: Thomas Reinhard, MD, Univers. Freiburg; Principal Investigator: Arnd Heiligenhaus, MD, Augenklinik am St.Franzsikus Hospital, Münster; Principal Investigator: Walter Sekundo, MD, Univers. Mainz; Principal Investigator: Theo Seiler, MD, IROC, Zürich; Principal Investigator: Atilla Osvald, MD, Univers Homurg, Saar; Principal Investigator: Jan M Vetter, MD, Univers. Mainz

Publications and helpful links

General Publications

• Spoerl E, Mrochen M, Sliney D, Trokel S, Seiler T. Safety of UVA-riboflavin cross-linking of the cornea. Cornea. 2007 May;26(4):385-9. doi: 10.1097/ICO.0b013e3180334f78.
• Koller T, Seiler T. [Therapeutic cross-linking of the cornea using riboflavin/UVA]. Klin Monbl Augenheilkd. 2007 Sep;224(9):700-6. doi: 10.1055/s-2007-963492. German.
• Seiler T, Hafezi F. Corneal cross-linking-induced stromal demarcation line. Cornea. 2006 Oct;25(9):1057-9. doi: 10.1097/01.ico.0000225720.38748.58.
• Wollensak G, Aurich H, Pham DT, Wirbelauer C. Hydration behavior of porcine cornea crosslinked with riboflavin and ultraviolet A. J Cataract Refract Surg. 2007 Mar;33(3):516-21. doi: 10.1016/j.jcrs.2006.11.015.

Helpful Links

• Click here for more information about this study: German Register of Corneal Cross Linking

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2007
• Primary Completion (Actual): November 1, 2024
• Study Completion (Estimated): November 1, 2027

Study Registration Dates

• First Submitted: November 19, 2007
• First Submitted That Met QC Criteria: November 19, 2007
• First Posted (Estimated): November 20, 2007

Study Record Updates

• Last Update Posted (Actual): June 18, 2026
• Last Update Submitted That Met QC Criteria: May 21, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Keywords: keratoconus; riboflavin; cornea; cross linking; UV-light
• Additional Relevant MeSH Terms: Eye Diseases; Keratoconus; Corneal Diseases; Sulfur Compounds; Organic Chemicals; Heterocyclic Compounds; Heterocyclic Compounds, 2-Ring; Heterocyclic Compounds, Fused-Ring; Therapeutics; Drug Therapy; Amides; beta-Lactams; Lactams; Cephalosporins; Thiazines; Combined Modality Therapy; Phototherapy; Photochemotherapy; Cephalexin; Cefaclor; Corneal Cross-Linking
• Other Study ID Numbers: CCL