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

Behandling av Keratoconus Med "Cornea Collagen Cross-linking" Uten Hornhinneepitelfjerning

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.

Study Overview

• Status: Completed
• Conditions: Keratoconus
• Intervention / Treatment: Procedure: CXL without epithelial removal; Procedure: CXL with epithelial removal

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.

• Study Type: Interventional
• Enrollment (Actual): 20
• Phase: Phase 2

Contacts and Locations

Study Locations

• Norway
  • Troms
    • Tromsoe, Troms, Norway, 9000
      • University Hospital North Norway

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 40 years (Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

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

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
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

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Best corrected distant visual acuity (BCDVA)	One year

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Corneal topographic keratoconus features	Corneal topographic features (and indices) showing keratectatic development will be followed (K-values, optical asymmetry, posterior surface protrusion and thickness).	One year

Collaborators and Investigators

• Sponsor: University Hospital of North Norway
• Investigators: Principal Investigator: Aleksandar Stojanovic, MD, University Hospital North Norway

Publications and helpful links

General Publications

• Stojanovic A, Zhou W, Utheim TP. Corneal collagen cross-linking with and without epithelial removal: a contralateral study with 0.5% hypotonic riboflavin solution. Biomed Res Int. 2014;2014:619398. doi: 10.1155/2014/619398. Epub 2014 Jun 22.

Study record dates

Study Major Dates

• Study Start: July 1, 2010
• Primary Completion (Actual): December 1, 2014
• Study Completion (Actual): December 1, 2014

Study Registration Dates

• First Submitted: August 12, 2010
• First Submitted That Met QC Criteria: August 12, 2010
• First Posted (Estimate): August 13, 2010

Study Record Updates

• Last Update Posted (Estimate): December 12, 2014
• Last Update Submitted That Met QC Criteria: December 11, 2014
• Last Verified: May 1, 2012

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Eye Diseases; Corneal Diseases; Keratoconus
• Other Study ID Numbers: CXL-TE UNN2010