Endophthalmitis in Eyes With the Boston Type I Keratoprosthesis: Incidence, Recurrence, Risk Factors, and Outcomes

Purpose: To determine the incidence and recurrence of Boston type I keratoprosthesis (KPro)-associated endophthalmitis, and its microbiological profile, risk factors, and outcomes. Methods: This is a retrospective study of 158 consecutive KPro procedures with a median follow-up of 78.4 months. Medical charts were reviewed for ocular history, contact lens and topical antibiotic use, visual acuity, and complications. For eyes with endophthalmitis, time to infection, culture results, and recurrences were collected. Cox regression analyses identified risk factors for endophthalmitis and compared the risk for visual failure, KPro retention, and globe loss between eyes with and without endophthalmitis. Results: The incidence and recurrence rates of endophthalmitis were of 1.7% and 6.0% per procedure-year, respectively. First episodes occurred at a median of 18.6 months. Eight of 18 episodes (44%) were culture positive, isolating mainly Gram-positive bacteria (7 [88%]). Previous ocular burn (hazard ratio: 7.34, 95% confidence interval: 1.91–28.15), infectious keratitis (5.09, 1.70–15.22), corneal melt (4.55, 1.50–13.83), and postoperative contact lens wear (4.19, 1.17–15.04) were risk factors. Eyes with endophthalmitis did not have a higher risk for visual failure (1.74, 0.78–3.91) but were more likely to not retain the KPro (2.81, 1.15–6.88) and undergo evisceration (2.81, 1.15–6.88). All eyes lost ≥ 2 lines of vision during the endophthalmitis episode. Conclusions: Endophthalmitis is rare but vision and globe threatening in eyes with KPro. Given the increased associated risk, corneal melts and infectious keratitis must be promptly treated, postoperative contact lenses should be considered on a case-by-case basis, and patients with ocular burns might require more aggressive antimicrobial prophylaxis.