First case of Raoultella terrigena endophthalmitis post-cataract surgery: case report and literature review

Abstract Background Infectious endophthalmitis is a severe complication of cataract surgery, often caused by common pathogens. Raoultella terrigena, a Gram-negative environmental bacterium, is an extremely rare cause of this condition, with no prior reports in the literature. This case highlights the importance of considering unusual pathogens in postoperative infections. Case presentation A 53-year-old male presented with severe ocular pain and decreased vision in the left eye on the first day after uneventful cataract surgery. Despite initial anti-inflammatory treatment, his condition worsened with the development of hypopyon and vitreous opacity. He underwent emergency pars plana vitrectomy (PPV) with intravitreal antibiotic injection. During PPV, vitreous empyema, retinal hemorrhage, capsular opacity, and pus accumulation under the capsular bag were observed; capsular irrigation and posterior capsulotomy were performed to facilitate removal of inflammatory debris and potential bacterial reservoirs. Vitreous culture confirmed Raoultella terrigena, which was sensitive to piperacillin-tazobactam and ceftazidime. At the 2-month postoperative follow-up, the visual acuity recovered to 1.0 Decimal (0.0 LogMAR, 6/6, 20/20). Conclusions Raoultella terrigena is a rare but potentially devastating cause of post-cataract endophthalmitis. Clinicians should maintain a high index of suspicion for acute, fulminant postoperative inflammation, even when caused by uncommon pathogens. Early diagnosis via vitreous sampling and prompt treatment with appropriate antibiotics, combined with PPV, are crucial for a favorable outcome.