An outbreak of Ralstonia pickettii endophthalmitis following intravitreal methotrexate injection

Purpose: To report an outbreak of endophthalmitis in three eyes of two patients following intravitreal methotrexate, caused by Ralstonia pickettii. Design: Retrospective, noncomparative, consecutive case series. Methods: Medical records and microbiology results of two patients who presented with acute endophthalmitis following intravitreal methotrexate injection in November 2013 were reviewed. Results: Following intravitreal injections, the patients experienced pain and decrease in vision in the affected eye within 24 hours of receiving intravitreal methotrexate injection. The presenting visual acuity in case 1 was 20/50 in the left eye. The presenting visual acuity in case 2 was hand motions in the right eye and counting fingers at 1 m in the left eye. Both the patients received methotrexate prepared in the same manufacturing facility. Both the patients underwent vitreous biopsy and intravitreal injection of vancomycin 1 mg/0.1 mL, amikacin 400 mu g/0.1 mL, and dexamethasone 400 mu g/0.1 mL. Microbiology cultures from vitreous, and used and unused vials of methotrexate from the same batch grew R. pickettii. After 8 months of follow-up, both the patients had visual acuity 20/60 or better. Conclusion: R. pickettii can be rarely associated with outbreak of endophthalmitis. Timely intervention can be associated with good visual outcome in such patients.