Infectious Keratitis After Boston Type 1 Keratoprosthesis Implantation

Purpose: To determine the incidence, clinical features, and outcomes of infectious keratitis after Boston type 1 keratoprosthesis (Kpro) implantation. Methods: Ten cases of infectious keratitis were identified in a retrospective chart review of 105 patients (126 eyes) who received Kpro between November 2004 and November 2010 at the Cincinnati Eye Institute and were followed for at least 1 month (range, 1-66 months; mean, 25 months). Results: The incidence was 7.9%. Patient diagnoses included 4 chemical injuries, 3 Stevens-Johnson syndrome, 2 ocular cicatricial pemphigoid, and 1 congenital aniridia. Kpro implantation was indicated in 2 eyes for a failed ocular surface and in 8 for penetrating keratoplasty failure. Four patients were contact lens intolerant or noncompliant. All were on topical vancomycin and moxifloxacin for prophylaxis and 2 were on topical amphotericin for prophylaxis. Three infiltrates were culture negative, 5 were fungal (3 Candida, 1 Fusarium, 1 Dactylaria constricta), and 2 were bacterial (Rhodococcus equi and Gram-negative cocci). All patients were managed with topical agents and 4 were given an oral antifungal agent. Four patients had Kpro removal with therapeutic penetrating keratoplasty and 1 had Kpro replacement. At final follow-up, only 2 patients retained their preinfection best vision. Risk factors for infectious keratitis included a diagnosis of cicatrizing conjunctivitis (Stevens-Johnson syndrome, ocular cicatricial pemphigoid, or chemical injury) and a history of persistent epithelial defect (P = 0.0003 and 0.0142, respectively). Contact lens wear, vancomycin use, and a history of systemic immunosuppression (or use at the time of infection) were not statistically significant risk factors. Conclusions: Infectious keratitis after Kpro can occur even when patients are on vancomycin and a fourth-generation fluoroquinolone for prophylaxis. Fungal organisms are a growing cause for concern, and we present the details of the first reported case of ocular D. constricta. The evolution of our management and prophylaxis strategy for fungal keratitis after Kpro implantation is also described.