Endogenous Klebsiella pneumoniae Endophthalmitis With Iris Abscess and Discordant Systemic and Ocular Culture Susceptibilities.

Purpose: To report a rare case of Klebsiella pneumoniae endogenous endophthalmitis complicated by iris abscess formation secondary to a septic urinary tract infection and liver abscess. Methods: A single case was reviewed. Results: A 57-year-old man with diabetes mellitus developed acute vision loss shortly after hospitalization for sepsis secondary to a K. pneumoniae urinary tract infection and liver abscess sensitive to cephalosporins. Ocular examination revealed hypopyon and severe intraocular inflammation. Initial treatment included intravitreal (IVT) vancomycin and ceftazidime with anterior chamber paracentesis. Intraocular cultures demonstrated newly acquired resistance to cephalosporins, prompting a switch to IVT moxifloxacin. Progressive inflammation necessitated pars plana vitrectomy and surgical debridement of an iris abscess. Postoperatively, weekly IVT moxifloxacin injections were administered for 3 weeks, resulting in resolution of infection. Conclusions: This case demonstrates rare iris abscess formation in K. pneumoniae endogenous endophthalmitis and underscores the importance of intraocular cultures in guiding targeted antimicrobial therapy.