Calcific band keratopathy on a keratoprosthesis

We describe a case of calcific band keratopathy in a patient with a nut-and-bolt keratoprosthesis. To our knowledge, this is the first reported case of this condition involving a prosthesis. The patient had initially suffered lye burns to both eyes. The prosthesis was placed in the right eye; numerous procedures had to be undertaken to maintain it. The patient was also treated surgically and pharmacologically for glaucoma. Seventeen years after initial implantation, white flakes appeared on the prosthesis in the classical band pattern. Pathologic examination revealed them to be calcific. Theories concerning corneal and contact lens calcific deposition are evaluated to assess their applicability to this case. We conclude that multiple factors may be responsible for calcific deposition on the keratoprosthesis and that this may call into question previous explanations of this disorder.