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Updated: Jul 23, 2026
Intravitreal Injection and Quantitation of Infection Parameters in a Mouse Model of Bacterial Endophthalmitis
Published on: February 6, 2021
Endophthalmitis prophylaxis by intracameral antibiotics: In vitro model comparing vancomycin,
1From Harkness Eye Institute (Libre), Columbia University Medical Center, New York, New York, and Norwalk Hospital (Libre), Norwalk, and the University of Connecticut (Mathews), Storrs, Connecticut, USA.
Purpose:
To compare the efficacy of intracameral vancomycin, cefuroxime, and moxifloxacin on postoperative bacterial endophthalmitis rates.
Setting:
Norwalk Hospital, Norwalk, Connecticut, USA.
Design:
Experimental study.
Methods:
Bacteria and intraocular lenses (IOLs) were incubated with vancomycin, cefuroxime, moxifloxacin, or combinations. Antibiotic concentrations were high, corresponding to clinical maximum intracameral doses (1.0 mg vancomycin or cefuroxime, 0.5 mg moxifloxacin), or low (one third of clinical maximum dose). The following bacteria were isolated from patients with endophthalmitis: 18 strains including 6 staphylococci, 6 streptococci, 3 pseudomonad, and 3 propionibacteria. Samples were diluted by half every 2 hours to model the half-life of intracameral antibiotics. At 24 hours, samples were vortexed to shake bacterial biofilms loose from the IOLs. The bacterial broth was plated and colonies were counted 24 hours later.
Results:
Efficacy against staphylococci was concentration dependent; all antibiotics were effective at high concentrations, while low concentrations were in general ineffective. Streptococci and propionibacteria were nearly eliminated by all antibiotics at low concentrations. Pseudomonads were most effectively treated by high-dose moxifloxacin and its combinations.
Conclusions:
Broadest coverage against common pathogens should be obtained by high-dose moxifloxacin (0.5 mg intracameral). Submaximum dosing, which could occur if aqueous is released to lower intraocular pressure after injection, compromises the efficacy against staphylococci and pseudomonads. All antibiotics, even at low doses, were effective against streptococci and propionibacteria, suggesting that many of the worst endophthalmitis outcomes could be prevented by intracameral use of any of the 3 antibiotics used in this study.
Insights
High-dose intracameral moxifloxacin offers the broadest coverage against common eye infection pathogens. Even low doses of vancomycin, cefuroxime, or moxifloxacin can prevent severe outcomes from streptococci and propionibacteria infections.
Area of Science:
- Ophthalmology
- Infectious Diseases
- Microbiology
Background:
- Postoperative bacterial endophthalmitis remains a significant concern following intraocular procedures.
- Intracameral antibiotics are frequently used prophylactically and therapeutically.
- Understanding the comparative efficacy of common intracameral antibiotics is crucial for optimizing treatment strategies.
Purpose of the Study:
- To compare the efficacy of intracameral vancomycin, cefuroxime, and moxifloxacin in preventing bacterial endophthalmitis.
- To evaluate the impact of antibiotic concentration on efficacy against common ocular pathogens.
Main Methods:
- An experimental study involving incubation of bacteria and intraocular lenses (IOLs) with vancomycin, cefuroxime, and moxifloxacin at high and low concentrations.
- Modeling of intracameral antibiotic half-life through serial dilution.
- Assessment of bacterial biofilm disruption and colony counts after 24 hours.
Main Results:
- Efficacy against staphylococci was concentration-dependent, with high concentrations being effective and low concentrations generally ineffective.
- Streptococci and propionibacteria were effectively eliminated by all tested antibiotics, even at low concentrations.
- Pseudomonads showed the best response to high-dose moxifloxacin and its combinations.
Conclusions:
- High-dose intracameral moxifloxacin (0.5 mg) provides the broadest coverage against common endophthalmitis pathogens.
- Submaximum antibiotic dosing compromises efficacy against staphylococci and pseudomonads.
- Intracameral vancomycin, cefuroxime, or moxifloxacin, even at low doses, can likely prevent severe outcomes associated with streptococci and propionibacteria.
