Intracameral moxifloxacin may lead as prophylactic antibiotic for cataract surgery

COS 2012, July 6 - Intracameral moxifloxacin appears to be the best prophylactic to use after cataract surgery, according to researchers who performed both a literature and general review of the topic. They also took into account their own experience with over 5,000 intraocular surgical procedures.

While numerous studies have evaluated the safety and efficacy of various intracameral antibiotics, there is no consensus on which is the best to use - if any at all - as prophylaxis after cataract surgery. Stephan Ong Tone, a PhD student at McGill University, in Montreal, spoke here in a presentation on the topic.

A key problem is the risk of postoperative endophthalmitis as a possible complication of cataract surgery. This outcome is rare but devastating. A literature review was performed of the three prophylactic intracameral antibiotics most often used: cefuroxime, vancomycin and moxifloxacin.

Ong Tone stated that European studies have demonstrated that cefuroxime is safe and effective at reducing the rate of endophthalmitis. However, it has big gaps in its coverage of antimicrobials including Gram-negative bacteria, methicillin-resistant Staphylococcus aureus and enterococci.

Studies also show that vancomycin is safe and effective at reducing the rate of endophthalmitis, especially against multiresistant Gram-positive bacteria. However, it is not effective against Gram-negative organisms and enterococci, Ong Tone said.

Moxifloxacin has been shown to be good at targeting eye tissue, he noted. It has broad-spectrum activity against several organisms including those that are Gram-positive, Gram-negative, atypical and anaerobic. It also shows dose-dependent rather than time-dependent kinetics for bacterial killing.

"The more recent appearance of dose-dependent resistance has led to an increase in the recommended prophylactic dose," said Ong Tone. Moxifloxacin is unrelated to other popular antibiotics for the treatment of endophthalmitis, making resistance to this antibiotic less likely.

While there are some advantages with moxifloxacin, he said all intracameral antibiotics reduce the rate of postoperative endophthalmitis.