Perioperative intracameral antibiotics should be standard practice during cataract surgery to prevent postoperative endophthalmitis.
Take-home: Perioperative intracameral antibiotics should be standard practice during cataract surgery to prevent postoperative endophthalmitis.
Dr. ArshinoffReviewed by Steve A. Arshinoff, MD, FRCSC
Toronto-Perioperative antibiotics, whether topical, subconjunctival, or intracameral, are used almost everywhere to prevent acute endophthalmitis, with varying protocols and evidence for efficacy. Intracameral antibiotics should be standard practice during cataract surgery to prevent postoperative endophthalmitis, as all studies of these drugs reported 80% to more than 90% reductions in endophthalmitis, according to Steve Arshinoff, MD, FRCSC, who is committed to use of the drugs.
A recent meta-analysis published by The Cochrane Collaboration (Gower et al. Perioperative antibiotics for prevention of acute endophthalmitis after cataract surgery, Cochrane Library 2013, Issue 7, July 2013) pointed to the effectiveness of intracameral antibiotics, but cautioned about the scarcity of published randomized controlled trials and the lack of availability of single-use intracameral antibiotic preparations.
The meta-analysis reviewed 4 Cochrane criteria qualifying randomized controlled trials that included 100,876 patients, studied 492 postoperative endophthalmitis papers, and evaluated preoperative antibiotics, intraoperative (intracameral, subconjunctival, or systemic), or postoperative antibiotic prophylaxis for acute endophthalmitis.
The conclusion of the meta-analysis, Dr. Arshinoff noted, was based primarily on the European Society of Cataract and Refractive Surgeons (ESCRS) study results because of inapplicability of the other studies to modern phacoemulsification surgery techniques. Also, according to Dr. Arshinoff, because it was generally in favor of the use of intracameral antibiotics, underscored the need for a single-use commercial preparation for intracameral injection, and suggested a study comparing moxifloxacin and intracameral cefuroxime.
Dr. Arshinoff is an instructor, Department of Ophthalmology and Vision Sciences, Faculty of Medicine, University of Toronto.
The authors concluded that “clinical trials with rare outcomes require very large sample sizes and are quite costly to conduct, thus, it is unlikely that additional clinical trials will be conducted to evaluate currently available prophylaxis. Practitioners should rely on current evidence to make informed decisions regarding prophylaxis choices.”
The Cochrane Review underscored the importance of decreasing the endophthalmitis incidence and commented that with about 30 million cataract surgeries performed annually, “the best estimate of the infection rate without intracameral antibiotics is 1:1,000 cases, that is, 30,000 cases per year, of which 10,000 cases become blind per year. Therefore, prevention of postoperative endophthalmitis is an important public health goal.”
Beyond the meta-analysis
However, Dr. Arshinoff noted that the meta-analysis did not include a number of studies of the effectiveness of intracameral antibiotics and a 2011 study on infection rates after immediately sequential bilateral cataract surgery (Arshinoff and Bastianelli, J Cataract Refract Surg 2011;37:2105-14). Drs. Arshinoff and Bastianelli concluded that the risk for postoperative endophthalmitis in immediately sequential bilateral cataract surgery appears to be at least as low as and possibly lower than published rates for unilateral surgery, particularly when recommended precautions are taken. Intracameral antibiotics significantly reduced the risk for postoperative endophthalmitis to 1:16,890 from 1:1,987 in their study of 101,341 cases (p < 0.0001).”
“Cochrane reports often cannot answer all questions,” Dr. Arshinoff said. “Not everything is amenable to large randomized controlled trials,” and, he added, 10 published studies of intracameral cephalosporin and four published studies of intracameral moxifloxacin all showed 80% to more than 90% reductions in postoperative endophthalmitis rates, but did not qualify for the Cochrane review.
Dr. Arshinoff recounted his own cataract surgery experience. From 1996 to 2013, he performed 11,074 cataract surgeries, more than three quarters of which were immediately sequential bilateral cataract surgeries. From 2004 to 2013, he used intracameral moxifloxacin in 6,277 cases and reported 2 endophthalmitis cases (1 case of incision trauma 2 weeks postoperatively, and thus unrelated to the antibiotic prophylaxis, and 1 case of unilateral moxifloxacin-resistant Staphylococcus epidermidis). Use of intracameral vancomycin in 4,797 cases form 1996 to 2004 resulted in no cases of endophthalmitis. When no intracameral antibiotics were used from 1980 to 1995 in about 6,000 unilateral cataract cases cataracts, he reported 1 case of endophthalmitis.
Based on his experience and that of other investigators, Dr. Arshinoff said he believes use of intracameral antibiotics should be standard practice during cataract surgery, as the Cochrane review concluded. His current anti-infective protocol includes moxifloxacin drops, 1 drop every 15 minutes x 4 preoperatively; betadine drops, 5% solution 10 minutes preoperatively; betadine scrub, 10% solution to paint ophthalmic area preoperatively; intracameral moxifloxacin at the end of the case (300 mcg in 0.2 cc balanced saline solution (BSS) (yields 1 mg/ml in anterior chamber); and postoperative moxifloxacin drops, 1 drop 6 times daily for 3 days, then 4 times daily for 7 days.
Dr. Arshinoff pointed out that Vigamox (moxiflxacin, Alcon) is readily available and non-preserved. It is critical to note that only Vigamox has been found to be safe for this use, he said. Moxeza (Alcon) moxifloxacin, is not a safe substitute, and other moxifloxacin preparations have not been studied. Vigamox is uncomplicated to dilute (3 cc Vigamox + 7 cc BSS). Importantly, if an infection does occur postoperatively, it will likely be moxifloxacin-resistant Staphylococcus, which is very sensitive to the usual endophthalmitis protocol of vancomycin and ceftazidime, whereas infections that occur with intracameral cefuroxime (a drug related to the usual endophthalmitis protocol drug, ceftazidime) are often with destructive resistant bacteria, such as enterobacter. Finally, drug allergy is also very rare with moxifloxacin.
Single-use injectable moxifloxacin became available in 2013 4 Quin PFS (manufacturer, Contacare Ophthalmics, Gujarat, India; marketer, Entod Pharmaceuticals Ltd., Mumbai, India). Moxifloxacin 0.5% (in water) prefilled syringe, 1-ml. Injectable cefuroxime 1 mg./0.1 cc became available from Thea Laboratories, France, in November 2012, which may be used for single or consecutive cases.
“All studies, irrespective of the background infection rate have demonstrated more than an 80% reduction (~10-fold) in endophthalmitis with intracameral antibiotics,” Dr. Arshinoff said. “Intracameral antibiotics should be used. Moxifloxacin is safe and moxifloxacin and cefuroxime are effective, however, there have been some cases of toxic anterior segment syndrome reported with cefuroxime, due to dilution errors.
“The Cochrane review suggested a randomized controlled study of intracameral cefuroxime versus intracameral moxifloxacin. I believe moxifloxacin 300 micrograms/0.2 cc offers the best option of the currently available antibiotics for intracameral antibacterial prophylaxis,” Dr. Arhsinoff concluded, adding that lower doses may be less effective due to occasional strains of staphylococci resistant to lower doses.
Steve A. Arshinoff, MD, FRCSC
Dr. Arshinoff is a consultant to Alcon Laboratories, Abbott Medical Optics, Bausch & Lomb, Croma, iMed Pharma, and ArcticDx.