Corneal stromal thinning observed in keratoconic eyes could result from an increased synthesis of MMP at the level of the anterior stroma and the corneal epithelium induced by an overexpression of the Extracellular Matrix Metalloproteinase Inducer (EMMPRIN) and Galectin-3 by epithelial cells. A differential expression of EMMPRIN, Galectin-3 and metalloproteinases (MMP) may be observed between the apex of the keratoconus and the peripheral cornea. Highlighting the implication of EMMPRIN and Galectin-3 could lead to the development of specific inhibitors to slow or to stop keratoconus evolution.

Inclusion Criteria:

• age > 18 years old
• Patient with keratoconus undergoing corneal collagen cross-linking (epithelium-off methods)
• Patient with keratoconus undergoing his first corneal graft for optical indication (control)

Exclusion Criteria:

• Patient with keratoconus undergoing corneal graft for tectonic indication
• Patient undergoing corneal refractive surgery (refractive photokeratectomy) with a normal topography, a normal slit lamp examination and no previous ophthalmic condition (control)
• pregnant or breast feeding patient
• patient under judiciary protection
• patient opposition to participate in the study

patients with keratoconus and controls subjects without keratoconus