Intravitreal cephalothin in experimental staphylococcal endophthalmitis

Area of Science:

• Ophthalmology
• Microbiology
• Pharmacology

Background:

• Bacterial endophthalmitis is a severe intraocular infection.
• Effective treatment strategies for bacterial endophthalmitis are crucial to prevent vision loss.

Purpose of the Study:

• To evaluate the efficacy and safety of intravitreal cephalothin for treating experimentally induced bacterial endophthalmitis in a rabbit model.
• To determine the optimal timing for intravitreal cephalothin administration.

Main Methods:

• Bacterial endophthalmitis was induced in rabbit eyes.
• Intravitreal injections of varying doses of cephalothin were administered.
• Intraocular structures were assessed for toxicity.
• Vitreous levels of cephalothin were measured over time.
• Clinical outcomes were compared between early and delayed treatment groups, and with control groups receiving alternative administration routes.

Main Results:

• A dose of 2 mg or less of intravitreal cephalothin showed no toxicity to intraocular structures.
• Vitreous cephalothin levels remained above the minimum inhibitory concentration for susceptible organisms for at least 32 hours post-injection of a 2 mg dose.
• Early intravitreal cephalothin injections successfully treated Staphylococcus-induced bacterial endophthalmitis.
• Delayed treatment resulted in the development of vitreous bands and posterior lens cataracts.
• Control eyes treated with intramuscular or subconjunctival cephalothin progressed to phthisis bulbi.

Conclusions:

• Intravitreal cephalothin is a safe and effective treatment for bacterial endophthalmitis when administered promptly.
• Early intervention is critical to prevent severe ocular complications and preserve vision.
• Alternative administration routes like intramuscular and subconjunctival injections are less effective for treating established bacterial endophthalmitis.