gms | German Medical Science

Long-term retention and host/ device interface stability are the most fundamental requirements for a successful permanent keratoprosthesis. The purpose of this study is to assess the retention rate and stability of a newly-modified model of the Boston Keratoprosthesis (previously known as the Dohlman-Doane Keratoprosthesis).

The surgical results and clinical follow-up of 173 consecutive patients implanted with the updated model of the Boston Keratoprosthesis as treatment for loss of corneal transparency associated with repeated corneal transplant failures were reviewed. This version of the keratoprosthesis has been available only for the past 36 months. Its enhancements include a Rev C design as well as a titanium locking ring to prevent spontaneous loosening of the back plate of the keratoprosthesis, a situation that had occurred on occasion with older models and required surgical revision to repair. Patients with end-stage autoimmune conditions (such as Stevens-Johnson syndrome and ocular cicatricial pemphigoid), as well as patients with severe chemical injury, were excluded from the study; these patients require an alternate surgical technique that is the subject of another study.

Follow-up ranged from 1 to 36 months. No patients required removal of the device. Only two patients required surgical revision of the keratoprosthesis for repair of localized melting at the host/ device interface; these two patients suffered from an underlying autoimmune disorder not diagnosed prior to surgery. Visual results, as expected, were varied and were principally dependent on the underlying visual potential of the eye from a retinal/ optic nerve stand-point.

The newly-modified model of the Boston Keratoprosthesis demonstrates excellent retention and host/ device interface stability over a medium-term follow-up period.