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Updated: Sep 28, 2026
Intravitreal Injection and Quantitation of Infection Parameters in a Mouse Model of Bacterial Endophthalmitis
Published on: February 6, 2021
Organism-Specific Clinical Features and Outcomes of Culture-Positive Endogenous Endophthalmitis: A Multicenter Cohort
Elizabeth Ciociola Kelly1, Russell Calderon2, Peter Weng1
1Wilmer Eye Institute, Johns Hopkins Hospital, Baltimore, MD, USA.
Objective:
Evaluate differences in presentation, management, and outcomes of culture-positive endogenous endophthalmitis by microbial pathogen.
Design:
Retrospective multicenter clinical cohort study PARTICIPANTS: Eyes with a clinical diagnosis of endogenous endophthalmitis that underwent anterior chamber paracentesis, intravitreal aspiration, or pars plana vitrectomy (PPV) and intravitreal injection of antimicrobials with no recent exogenous risk factors.
Methods:
Clinical presentation, culture characteristics, treatment and outcomes for culture-positive endogenous endophthalmitis from 2012-2024 at nine academic tertiary referral centers stratified by microbial pathogen were reported. Multivariable mixed-effects models were used to determine predictors of final visual acuity (VA).
Main Outcomes And Measures:
Final VA, retinal detachment, enucleation.
Results:
305 eyes from 261 patients were included: Staphylococcus aureus 115 (37.7%), Streptococcus 41 (13.4%), other gram-positive 29 (9.5%), gram-negative 47 (15.4%), fungal 59 (19.3%), and polymicrobial 14 (4.6%) infections. Blood cultures were positive in 202/305 eyes (66.2%), vitreous in 95 (31.1%), and aqueous in 27 (8.9%); concordant organism growth in paired blood and eye cultures occurred in 24/39 cases (62%). Fungal cases had higher rates of immunosuppression and intravenous drug use (p<0.05), while gram-negative cases more often had urinary sources (p<0.001). Presenting and final VA varied across groups (presenting mean logMAR 1.78-2.14 for most bacteria vs 1.30 for fungal, p<0.001; final mean logMAR 1.31-1.75 for bacteria vs 1.13 for fungal, p=0.06). Retinal detachment was most frequent with Staphylococcus aureus and Streptococcus. Enucleation was highest with gram-negative organisms (27.7%), driven by Serratia (85.7%, p=0.05). In adjusted mixed-effects models, worse presenting VA was the most consistent predictor of poorer final VA across groups; in Staphylococcus aureus and Streptococcus infections, systemic infection source, culture positivity, and need for PPV were predictors of final VA.
Conclusions:
In this multicenter cohort, organism groups were associated with distinct presentations, sources, management, and outcomes. Low intraocular culture yield and imperfect concordance with blood cultures complicate pathogen-directed therapy. Presenting VA is the dominant prognostic factor, but gram-negative infections-particularly Serratia-carry markedly higher risk of globe loss. These findings support organism-informed clinical decision-making and highlight the need for improved intraocular diagnostics and targeted interventions.
