search
Back to results

Collagen Crosslinking for Keratoconus - a Randomized Controlled Clinical Trial (CXL-RCT)

Primary Purpose

Keratoconus

Status
Active
Phase
Phase 3
Locations
Sweden
Study Type
Interventional
Intervention
Corneal Collagen Crosslinking
Sponsored by
Sahlgrenska University Hospital, Sweden
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional treatment trial for Keratoconus focused on measuring Collagen crosslinking, Keratoconus

Eligibility Criteria

18 Years - 30 Years (Adult)All SexesDoes not accept healthy volunteers

Inclusion Criteria:

  • Keratoconus diagnosis determined clinically and topographically (KISA%- index)

  • Significant progression is defined as change (increase) of Kmax by at least

    1D from baseline at 6 months and/or change (increase) of Sim-K-ast by at least 1D from baseline at 6 months. Kmax is defined as the steepest radius of curvature (either the maximum simulated K-reading or the maximum K-reading in the 3-mm zone or the 5-mm zone) of the anterior corneal surface that progressed the most during 6 months observation

  • Ability to stop contact lens (rigid and soft) wear at least two weeks prior to next exam
  • Signed written informed consent

Exclusion Criteria:

  • Age < 18 years
  • Pregnancy
  • Breast feeding
  • History of corneal surgery
  • History of ocular herpes simplex infection
  • Minimal corneal thickness < 300 micrometers
  • Recurrent corneal erosions
  • Other corneal (e g endothelial) or conjunktival diseases
  • Neurodermatitis
  • Severe forms av atopic disease
  • Collagenoses, autoimmune or other systemic disease
  • Systemic treatment with high doses of steroids
  • Severe scarring och striae of the cornea

Relative exclusion criteria:

  • Kmax > 58D
  • Minimal corneal thickness < 400 micrometers (a modified CXL-treatment will be used swelling the cornea before UV-illumination treatment).

Sites / Locations

  • Department of Ophthalmology, Sahlgrenska University Hospital

Arms of the Study

Arm 1

Arm 2

Arm Type

Active Comparator

No Intervention

Arm Label

Corneal Collagen Crosslinking

Control group

Arm Description

The keratokonic eye which progresses most is included and randomized. Significant progression is defined in the eligibility criteria section. If randomized to the treatment arm the cornea is treated with collagen crosslinking as described below.

The keratokonic eye which progresses most is included and randomized to either the treatment group (CXL) or the control group.

Outcomes

Primary Outcome Measures

Kmax
Kmax is defined as the steepest radius of curvature of the anterior corneal surface. It is measured by Scheimpflug-topography (Pentacam, Oculus Inc.). An increase of less than 1 diopter (D) from baseline at 12 months is defined as non-progression.

Secondary Outcome Measures

Sim-K-astigmatism
Sim-K-astigmatism (Sim-K-ast) is defined as the absolute amount of anterior corneal astigmatism related to the Sim-Ks as measured by Scheimpflug-topography (Pentacam, Oculus Inc.). An increase of less than 1 D from baseline at 12 months is defined as non progression.
MRSE
Manifest Refractive Spherical Equivalent. The spherical equivalent is calculated by algebraic addition of the spherical power and half the cylindrical power of an eye. An eye with a specific spherical equivalent power has the closest overall effect to a given toric lens. A decrease of less than 0.5 D from baseline at 12 months is defined as non-progression.
UCDVA
UCDVA is defined as the uncorrected distance visual acuity measured with an Early Treatment of Diabetic Retinopathy Study (ETDRS)-chart and expressed in numbers of letters. A decrease of less than 5 letters (one line) from baseline at 12 months is defined as stable BCDVA.
BSCDVA
BSCDVA is defined as the the best spectacle corrected distance visual acuity measured with an ETDRS-chart and expressed in numbers of letters. A decrease of less than 5 letters (one line) from baseline at 12 months is defined as stable BCDVA.

Full Information

First Posted
May 21, 2012
Last Updated
March 14, 2023
Sponsor
Sahlgrenska University Hospital, Sweden
Collaborators
Göteborg University
search

1. Study Identification

Unique Protocol Identification Number
NCT01604135
Brief Title
Collagen Crosslinking for Keratoconus - a Randomized Controlled Clinical Trial
Acronym
CXL-RCT
Official Title
Collagen Crosslinking for Keratoconus - a Randomized Controlled Clinical Trial
Study Type
Interventional

2. Study Status

Record Verification Date
March 2023
Overall Recruitment Status
Active, not recruiting
Study Start Date
May 2012 (Actual)
Primary Completion Date
April 2024 (Anticipated)
Study Completion Date
April 2024 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
Sahlgrenska University Hospital, Sweden
Collaborators
Göteborg University

4. Oversight

Data Monitoring Committee
Yes

5. Study Description

Brief Summary
The purpose of this study is to determine whether corneal collagen crosslinking is effective in the treatment of progressive keratoconus.
Detailed Description
Keratoconus is a noninflammatory, asymmetrical, progressive corneal ectasia caused by biomechanical instability of the corneal stroma. Treatment modalities are primarily glasses or contact lenses. It has been estimated that one out of five patients will progress to such an extent that a corneal transplant is necessary to regain useful vision. Corneal collagen crosslinking (CXL) is a treatment modality that intends to halt progression of keratoconus. This study investigates the efficacy av CXL in stabilizing the cornea in keratoconus by means of a randomized controlled clinical trial. Participants are eligible for inclusion if progressive keratoconus is confirmed and the inclusion criteria are met. Follow-up after inclusion is at 1 week (treatment group), 1, 3, 6 and 12 months. Pre- and post-inclusion examinations include measurement of uncorrected distance visual acuity (UCDVA), best spectacle corrected distance visual acuity (BSCDVA), Scheimpflug-topography and slitlamp examination.

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Keratoconus
Keywords
Collagen crosslinking, Keratoconus

7. Study Design

Primary Purpose
Treatment
Study Phase
Phase 3
Interventional Study Model
Parallel Assignment
Masking
None (Open Label)
Allocation
Randomized
Enrollment
36 (Actual)

8. Arms, Groups, and Interventions

Arm Title
Corneal Collagen Crosslinking
Arm Type
Active Comparator
Arm Description
The keratokonic eye which progresses most is included and randomized. Significant progression is defined in the eligibility criteria section. If randomized to the treatment arm the cornea is treated with collagen crosslinking as described below.
Arm Title
Control group
Arm Type
No Intervention
Arm Description
The keratokonic eye which progresses most is included and randomized to either the treatment group (CXL) or the control group.
Intervention Type
Device
Intervention Name(s)
Corneal Collagen Crosslinking
Other Intervention Name(s)
Cross-Linking Procedure UV-X 2000, UV-X 2000 Illumination system, Innocross-R 0.1% dextran 20% solution, Innocross-R hypotonic riboflavin 0.1%
Intervention Description
Keratoconic corneas that show significant progression as specified in the inclusion criteria section will receive one single treatment with CXL if randomized to the treatment arm. A treatment protocol based on 30 minutes dropping with riboflavin/dextran solution and 10 minutes UV-illumination treatment will be used.
Primary Outcome Measure Information:
Title
Kmax
Description
Kmax is defined as the steepest radius of curvature of the anterior corneal surface. It is measured by Scheimpflug-topography (Pentacam, Oculus Inc.). An increase of less than 1 diopter (D) from baseline at 12 months is defined as non-progression.
Time Frame
12 months
Secondary Outcome Measure Information:
Title
Sim-K-astigmatism
Description
Sim-K-astigmatism (Sim-K-ast) is defined as the absolute amount of anterior corneal astigmatism related to the Sim-Ks as measured by Scheimpflug-topography (Pentacam, Oculus Inc.). An increase of less than 1 D from baseline at 12 months is defined as non progression.
Time Frame
12 months
Title
MRSE
Description
Manifest Refractive Spherical Equivalent. The spherical equivalent is calculated by algebraic addition of the spherical power and half the cylindrical power of an eye. An eye with a specific spherical equivalent power has the closest overall effect to a given toric lens. A decrease of less than 0.5 D from baseline at 12 months is defined as non-progression.
Time Frame
12 months
Title
UCDVA
Description
UCDVA is defined as the uncorrected distance visual acuity measured with an Early Treatment of Diabetic Retinopathy Study (ETDRS)-chart and expressed in numbers of letters. A decrease of less than 5 letters (one line) from baseline at 12 months is defined as stable BCDVA.
Time Frame
12 months
Title
BSCDVA
Description
BSCDVA is defined as the the best spectacle corrected distance visual acuity measured with an ETDRS-chart and expressed in numbers of letters. A decrease of less than 5 letters (one line) from baseline at 12 months is defined as stable BCDVA.
Time Frame
12 months

10. Eligibility

Sex
All
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
30 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: Keratoconus diagnosis determined clinically and topographically (KISA%- index) Significant progression is defined as change (increase) of Kmax by at least 1D from baseline at 6 months and/or change (increase) of Sim-K-ast by at least 1D from baseline at 6 months. Kmax is defined as the steepest radius of curvature (either the maximum simulated K-reading or the maximum K-reading in the 3-mm zone or the 5-mm zone) of the anterior corneal surface that progressed the most during 6 months observation Ability to stop contact lens (rigid and soft) wear at least two weeks prior to next exam Signed written informed consent Exclusion Criteria: Age < 18 years Pregnancy Breast feeding History of corneal surgery History of ocular herpes simplex infection Minimal corneal thickness < 300 micrometers Recurrent corneal erosions Other corneal (e g endothelial) or conjunktival diseases Neurodermatitis Severe forms av atopic disease Collagenoses, autoimmune or other systemic disease Systemic treatment with high doses of steroids Severe scarring och striae of the cornea Relative exclusion criteria: Kmax > 58D Minimal corneal thickness < 400 micrometers (a modified CXL-treatment will be used swelling the cornea before UV-illumination treatment).
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Madeleine Zetterberg, MD, PhD
Organizational Affiliation
Sahlgrenska University Hospital, Sweden
Official's Role
Study Chair
First Name & Middle Initial & Last Name & Degree
Margareta Claesson, MD, PhD
Organizational Affiliation
Sahlgrenska University Hospital, Sweden
Official's Role
Study Director
Facility Information:
Facility Name
Department of Ophthalmology, Sahlgrenska University Hospital
City
Mölndal
State/Province
Västra Götalandsregionen
ZIP/Postal Code
43180
Country
Sweden

12. IPD Sharing Statement

Citations:
PubMed Identifier
21183110
Citation
Hersh PS, Greenstein SA, Fry KL. Corneal collagen crosslinking for keratoconus and corneal ectasia: One-year results. J Cataract Refract Surg. 2011 Jan;37(1):149-60. doi: 10.1016/j.jcrs.2010.07.030.
Results Reference
background
PubMed Identifier
21700105
Citation
Greenstein SA, Fry KL, Hersh PS. Corneal topography indices after corneal collagen crosslinking for keratoconus and corneal ectasia: one-year results. J Cataract Refract Surg. 2011 Jul;37(7):1282-90. doi: 10.1016/j.jcrs.2011.01.029.
Results Reference
background
PubMed Identifier
12719068
Citation
Wollensak G, Spoerl E, Seiler T. Riboflavin/ultraviolet-a-induced collagen crosslinking for the treatment of keratoconus. Am J Ophthalmol. 2003 May;135(5):620-7. doi: 10.1016/s0002-9394(02)02220-1.
Results Reference
background
PubMed Identifier
24393351
Citation
Wittig-Silva C, Chan E, Islam FM, Wu T, Whiting M, Snibson GR. A randomized, controlled trial of corneal collagen cross-linking in progressive keratoconus: three-year results. Ophthalmology. 2014 Apr;121(4):812-21. doi: 10.1016/j.ophtha.2013.10.028. Epub 2014 Jan 6.
Results Reference
background

Learn more about this trial

Collagen Crosslinking for Keratoconus - a Randomized Controlled Clinical Trial

We'll reach out to this number within 24 hrs