Collagen Crosslinking for Keratoconus - a Randomized Controlled Clinical Trial (CXL-RCT)
The purpose of this study is to determine whether corneal collagen crosslinking is effective in the treatment of progressive keratoconus.
Pellucid Marginal Degeneration
Device: Corneal Collagen Crosslinking
|Study Design:||Allocation: Randomized
Endpoint Classification: Efficacy Study
Intervention Model: Parallel Assignment
Masking: Open Label
Primary Purpose: Treatment
|Official Title:||Collagen Crosslinking for Keratoconus - a Randomized Controlled Clinical Trial|
- Kmax [ Time Frame: 12 months ] [ Designated as safety issue: No ]Kmax is defined as the steepest radius of curvature of the anterior corneal surface as 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.
- Sim-K-astigmatism [ Time Frame: 12 months ] [ Designated as safety issue: No ]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 [ Time Frame: 12 months ] [ Designated as safety issue: No ]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 [ Time Frame: 12 months ] [ Designated as safety issue: No ]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 [ Time Frame: 12 months ] [ Designated as safety issue: No ]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.
|Study Start Date:||May 2012|
|Estimated Study Completion Date:||May 2015|
|Estimated Primary Completion Date:||May 2015 (Final data collection date for primary outcome measure)|
Active Comparator: Corneal Collagen Crosslinking
The keratokonic eye which progresses most is included and randomized. Significant progression is defined in the eligibility criteria section. When assessing progression, weighting of the relevant parameters will be as follows: Kmax>Sim-K-ast>S.E. If, for example, the right eye decreased more in S.E. than the left but the left increased more in Kmax, the left eye will be included. If randomized to the treatment arm the cornea is treated with collagen crosslinking as described below.
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.
No Intervention: Control group
The keratokonic eye which progresses most is included and randomized to either the treatment group (CXL) or the control group.
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 relatively new treatment modality intended 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.
|Contact: Wolf K Wonneberger, MDfirstname.lastname@example.org|
|Contact: Madeleine Zetterberg, MD, PhDemail@example.com|
|Department of Ophthalmology, Sahlgrenska University Hospital||Recruiting|
|Mölndal, Västra Götalandsregionen, Sweden, 43180|
|Principal Investigator: Wolf K Wonneberger, MD|
|Study Chair:||Madeleine Zetterberg, MD, PhD||Sahlgrenska University Hospital, Sweden|
|Study Director:||Margareta Claesson, MD, PhD||Sahlgrenska University Hospital, Sweden|