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Transepithelial Corneal Collagen Cross-linking (CXL) in Treatment of Keratoconus

This study has been completed.
Information provided by (Responsible Party):
University Hospital of North Norway Identifier:
First received: August 12, 2010
Last updated: December 11, 2014
Last verified: May 2012

Transepithelial CXL (performed without epithelial removal) seem to have similar clinical effect on keratoconic eyes compared to the standard CXL (which includes epithelial removal). The current study attempts to prove that hypothesis.

A prospective, controlled, randomized, contralateral trial, will involve one eye of the patient to be treated with transepithelial CXL, while the control eye will be treated with the standard CXL. Totally 20 patients (age >18 and <40 years) referred by an ophthalmologist to the eye department of the University Hospital North Norway for CXL treatment of bilateral progressive keratoconus, will be recruited.

Condition Intervention Phase
Keratoconus Procedure: CXL without epithelial removal Procedure: CXL with epithelial removal Phase 2

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: None (Open Label)
Primary Purpose: Treatment
Official Title: Behandling av Keratoconus Med "Cornea Collagen Cross-linking" Uten Hornhinneepitelfjerning

Resource links provided by NLM:

Further study details as provided by University Hospital of North Norway:

Primary Outcome Measures:
  • Best corrected distant visual acuity (BCDVA) [ Time Frame: One year ]

Secondary Outcome Measures:
  • Corneal topographic keratoconus features [ Time Frame: One year ]
    Corneal topographic features (and indices) showing keratectatic development will be followed (K-values, optical asymmetry, posterior surface protrusion and thickness).

Enrollment: 20
Study Start Date: July 2010
Study Completion Date: December 2014
Primary Completion Date: December 2014 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: CXL without epithelial removal
Application of Riboflavin and the consequent UV-irradiation with intact corneal epithelium
Procedure: CXL without epithelial removal
UV-radiation of a Riboflavin saturated cornea without prior epithelial removal
Active Comparator: CXL with epithelial removal
Corneal epithelial removal prior to Riboflavin and the consequent UV-irradiation
Procedure: CXL with epithelial removal
UV-radiation of a Riboflavin saturated cornea after surgical epithelial removal has been performed

Detailed Description:
CXL appears to hinder the development of keratoconus by strengthening the cross-bindings in the corneal stroma with a resultant increase in corneal biomechanical strength of up to 300%. The method was introduced in the mid-nineties and has been approved for use in the EU countries since 2007. Standard treatment protocol, involving the removal of the corneal epithelium before the Riboflavin application, has been used. In order to avoid potential complications following removal of the epithelium (infection, delayed healing, scar formation, as well as discomfort and pain), a modified procedure where the epithelium is kept intact, so called transepithelial CXL, has been suggested. According to the preliminary results of the published retrospective studies, no significant difference in the clinical effect between the standard CXL with epithelial removal and the transepithelial CXL was found.

Ages Eligible for Study:   18 Years to 40 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   No

Inclusion Criteria:

  • Documented keratoconus progression in both eyes during the last 12 months before the treatment - decrease in best spectacle-corrected visual acuity (BSCVA) and/or increase in cornea curvature or asymmetry
  • Corneal thickness ≥400μm at the thinnest point
  • Age range from 18 to 40
  • Amsler-Krumeich classification graded stage I to III

Exclusion Criteria:

  • Corneal thickness <400μm at the thinnest point
  • History of viral keratitis
  • Severe dry eye
  • Concurrent corneal infections
  • Previous ocular surgery
  • Hard contact lens wear for ≤4 weeks before baseline examination
  Contacts and Locations
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Please refer to this study by its identifier: NCT01181219

University Hospital North Norway
Tromsoe, Troms, Norway, 9000
Sponsors and Collaborators
University Hospital of North Norway
Principal Investigator: Aleksandar Stojanovic, MD University Hospital North Norway
  More Information

Publications automatically indexed to this study by Identifier (NCT Number):
Responsible Party: University Hospital of North Norway Identifier: NCT01181219     History of Changes
Other Study ID Numbers: CXL-TE UNN2010
Study First Received: August 12, 2010
Last Updated: December 11, 2014

Additional relevant MeSH terms:
Corneal Diseases
Eye Diseases
Vitamin B Complex
Growth Substances
Physiological Effects of Drugs
Photosensitizing Agents
Dermatologic Agents processed this record on September 20, 2017