Characteristics of endophthalmitis in patients with the Boston keratoprosthesis.

Purpose: To determine the characteristics of endophthalmitis in patients with the Boston keratoprosthesis.
Methods: Retrospective chart review of 4 out of 35 patients who underwent implantation of the Boston keratoprosthesis on the Wills Eye Cornea service between 2001 and 2007 and developed infectious endophthalmitis.
Results: All 4 patients had keratoprosthesis surgery due to previous corneal transplant failure. The incidence of endophthalmitis was 11.4%. All patients were on topical antibiotic prophylaxis with a fluoroquinolone and 1 of the 4 patients was also using vancomycin drops. All 4 patients underwent a tap and inject and were admitted for intensive intravenous and topical antibiotics for 3 to 7 days. Culture positive results were found in 3 of the 4 vitreous samples: 2 coagulase-negative Staphylococcus, and 1 Pseudomonas and Staphylococcus aureus. Minimum Inhibitory Concentration data showed high resistance to fourth-generation fluoroquinolone antibiotics in all isolates. All patients recovered significant vision, except 1 patient who developed fluctuating vision secondary to vitreoretinal traction bands, which developed secondary to the endophthalmitis.
Conclusion: Endophthalmitis can occur after Boston keratoprosthesis at a significant rate, even in low-risk patients on prophylactic antibiotic drops. Given our experience with these patients and vancomycin, we recommend its prophylactic use. The increasing resistance of gram-positive organisms to fluoroquinolones and the need for close patient follow-up to encourage adherence to preventive regimens are further supported in this report.