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Updated: Aug 14, 2026
Intravitreal Injection and Quantitation of Infection Parameters in a Mouse Model of Bacterial Endophthalmitis
Published on: February 6, 2021
Experimental pseudomonal posttraumatic endophthalmitis in a swine model. Treatment with ceftazidime, amikacin, and
D V Alfaro1, S J Hudson, E J Kasowski
1Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814-4799, USA.
Purpose:
To compare the intravitreal efficacy of three separately administered antibiotics (imipenem, ceftazidime, and amikacin) in limiting the intraocular inflammation and tissue destruction caused by posttraumatic pseudomonal endophthalmitis.
Methods:
Thirty-three Yorkshire pigs each received a surgically induced scleral injury to the right eye. After repair, each eye was injected with 22,000 colony-forming units of live Pseudomonas aeruginosa. Pigs then were randomly grouped into a natural-history-of-infection group in which no treatment was given (n = 9) or into groups treated with the following: intravitreal imipenem (n = 6), ceftazidime (n = 6), amikacin (n = 6), or normal saline (n = 6). Pigs then were observed clinically for 18-24 hours after surgery and enucleated for histopathologic examination.
Results:
Clinical examinations revealed significantly less posterior segment inflammation in pigs treated with amikacin and imipenem than in pigs in the natural history or saline control groups, based on the Wilcoxon rank sum test (P < .05). Histopathologic examinations showed similar results, with less intraocular inflammation and retinal destruction in pigs treated with amikacin and imipenem, whereas the inflammation in pigs treated with ceftazidime did not differ significantly from that in control pigs.
Conclusion:
Intravitreal antibiotic treatment with imipenem or amikacin appears to limit intraocular inflammation and retinal tissue damage when given early in the course of posttraumatic pseudomonal endopthalmitis. Results with ceftazidime are less conclusive.
Insights
Early intravitreal imipenem or amikacin effectively reduced inflammation and retinal damage in experimental pseudomonal endophthalmitis. Ceftazidime showed less conclusive results in limiting posttraumatic eye infections.
Area of Science:
- Ophthalmology
- Infectious Diseases
- Microbiology
Background:
- Posttraumatic endophthalmitis is a severe ocular infection often caused by bacteria.
- Pseudomonas aeruginosa is a common and aggressive pathogen implicated in endophthalmitis, leading to significant intraocular inflammation and tissue destruction.
- Effective early treatment is crucial to prevent vision loss.
Purpose of the Study:
- To compare the efficacy of intravitreal imipenem, ceftazidime, and amikacin in managing posttraumatic pseudomonal endophthalmitis.
- To evaluate the impact of these antibiotics on intraocular inflammation and retinal tissue damage.
- To determine the optimal antibiotic choice for early intervention.
Main Methods:
- A rabbit model of surgically induced scleral injury followed by Pseudomonas aeruginosa inoculation was used.
- Pigs were randomly assigned to treatment groups: imipenem, ceftazidime, amikacin, normal saline, or a natural history group.
- Clinical and histopathologic examinations were performed to assess inflammation and tissue damage.
Main Results:
- Amikacin and imipenem significantly reduced posterior segment inflammation and retinal destruction compared to control groups.
- Ceftazidime treatment did not show a significant difference in inflammation compared to controls.
- Histopathologic findings corroborated clinical observations, highlighting the protective effects of amikacin and imipenem.
Conclusions:
- Intravitreal imipenem and amikacin are effective in limiting inflammation and retinal damage in early posttraumatic pseudomonal endophthalmitis.
- Ceftazidime's efficacy in this context is less conclusive.
- Early administration of appropriate intravitreal antibiotics is vital for managing severe ocular infections.
