Corneal Collagen Crosslinking and Intacs for Keratoconus and Ectasia

This study will determine the efficacy of corneal collagen crosslinking (CXL) combined with Intacs for the treatment of keratoconus and corneal ectasia. The goal of CXL is to decrease the progression of keratoconus, while Intacs has been shown to decrease corneal steepness in keratoconus. This study will attempt to determine the relative efficacy of the two procedures either performed at the same session versus CXL performed 3 months after Intacs.

The purpose of this is to ascertain the possible additive effect of the two treatments to both improve the quality of the corneal optics (i.e. improve corneal topography regularity) and to stabilize the cornea. Previous investigations have shown that Intacs surgery, indeed, does improve corneal topography and improve contact lens tolerance and spectacle corrected visual acuity, as well as uncorrected visual acuity in some patients. Investigations of CXL have shown the procedure not only to decrease keratoconus progression, but also to decrease the steepness of the cone and improve uncorrected and best corrected visual acuity in some cases. Since the mechanism of improvement differs between the procedures, this suggests a potential additive effect of the two on the patient's ultimate visual outcome. Thus, the patient would be afforded two potential benefits: (1) the potential of a more robust visual outcome and (2) stabilization of the keratoconic cornea on the longer term.