Collagen Crosslinking for Keratoconus - a Randomized Controlled Clinical Trial

Keratoconus Clinical Trial

— CXL-RCT  

Official title:

Collagen Crosslinking for Keratoconus - a Randomized Controlled Clinical Trial

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT01604135
• Other study ID #: DNR-949-11
• Status: Active, not recruiting
• Phase: Phase 3
• Start date: May 2012
• Est. completion date: April 2025

Study information

• Verified date: June 2024
• Source: Sahlgrenska University Hospital, Sweden
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

The purpose of this study is to determine whether corneal collagen crosslinking is effective in the treatment of progressive keratoconus.

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.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 36
• Est. completion date: April 2025
• Est. primary completion date: April 2025
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years to 30 Years

Eligibility

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).

Related Conditions & MeSH terms

• Keratoconus

Intervention

Device:
• Corneal Collagen Crosslinking
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.

Locations

Country	Name	City	State
Sweden	Department of Ophthalmology, Sahlgrenska University Hospital	Mölndal	Västra Götalandsregionen

Sponsors (2)

Lead Sponsor	Collaborator
Sahlgrenska University Hospital, Sweden	Göteborg University

Country where clinical trial is conducted

Sweden, 

References & Publications (4)

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. — View 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. — View 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. — View 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. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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.	12 months
Secondary	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.	12 months
Secondary	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.	12 months
Secondary	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.	12 months
Secondary	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.	12 months