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

Sahlgrenska University Hospital

Status and phase: Active, not recruiting; Phase 3

Conditions: Keratoconus

Treatments: Device: Corneal Collagen Crosslinking

Study type: Interventional

Funder types: Other

Identifiers

NCT01604135

DNR-949-11

Details and patient eligibility

About

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

Full 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.

Enrollment: 36 patients

Sex: All

Ages: 18 to 30 years old

Volunteers: No 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).

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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36 participants in 2 patient groups

Corneal Collagen Crosslinking

Active Comparator group

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.

Treatment:

Device: Corneal Collagen Crosslinking

Control group

No Intervention group

Description:

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