A complete intrastromal ring, MyoRing (Dioptex, GmbH, Linz, Austria), suggested by Albert Daxer in 2007, is a relatively new technique that has been demonstrated to treat keratoconus safely and effectively.Corneal collagen crosslinking (CXL), introduced by Wollensak et al. in 2003, has become a standard treatment for progressive keratoconus to slow or possibly stop progression of disease.

The formation of the stromal pocket during MyoRing implantation offers the opportunity for simultaneous introduction of riboflavin 0.1% into the pocket followed by UVA irradiation to provide combined treatment in patients with progressive keratoconus.

Inclusion Criteria:

• >18 years old
• a diagnosis of keratoconus, intolerance for contact lenses or glasses
• a documented progression of disease. This progression was defined by the following changes over 1 year: an increase of the steepest K by 1.0 diopter (D) or more in manifest cylinder, or an increase of 0.5 D or more in manifest spherical equivalent (SE) refraction by repeated keratotopography ODP-scan ARK-1000 (Nidek, Japan)

Exclusion Criteria:

• minimal pachymetry of less than 380 μm,
• a history of previous ocular pathology or ocular surgery;
• pregnancy or breastfeeding;
• corneal scarring.