Clinical Trial: Collagen Crosslinking for Keratoconus - a Randomized Controlled Clinical Trial

Study Status: Recruiting
Recruit Status: Recruiting
Study Type: Interventional

Official Title: Collagen Crosslinking for Keratoconus - a Randomized Controlled Clinical Trial

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

Detailed Summary:

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.


Sponsor: Sahlgrenska University Hospital, Sweden

Current Primary Outcome: Kmax [ Time Frame: 12 months ]

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.


Original Primary Outcome: Kmax [ Time Frame: 12 months ]

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.


Current Secondary Outcome:

  • Sim-K-astigmatism [ Time Frame: 12 months ]
    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 ]
    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 ]
    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 ]
    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.


Original Secondary Outcome: Same as current

Information By: Sahlgrenska University Hospital, Sweden

Dates:
Date Received: May 21, 2012
Date Started: May 2012
Date Completion: May 2019
Last Updated: April 22, 2016
Last Verified: April 2016