Secondary corneal amyloidosis in keratoconus.

We describe the case of a 37-year-old caucasian man with a history of keratoconus and long-term hard contact lens wear. Histological analysis of the corneal button after penetrating keratoplasty revealed staining with Congo red and apple green birefringence detected using polarized light. In the absence of other systemic or ocular pathology, the authors infer this amyloid deposition to be secondary to keratoconus and endeavor to discuss the possible etiopathogenesis of the disease.