Iontophoresis for delivering ophthalmic compositions (in particular. collyriums) preferably containing riboflavin, or other cross-linking agents, designed to imbibe the corneal stroma in the practice of the corneal collagen cross-linking (CXL) for the keratoconus treatment, and the corresponding ophthalmic compositions adapted to be administrated by iontophoresis in the treatment of keratoconus by corneal collagen cross-linking. Additionally, an ophthalmic composition for the treatment of keratoconus by corneal iontophoresis characterized by the fact that it includes cross-linking agents having buffering properties and whose initial pH value is included between 5 and 6, and/or bio-enhancers, and/or photo-enhancers.
