Eyeworld

EW CATARACT 46 November 2017 YES connect by Liz Hillman EyeWorld Staff Writer What young eye surgeons need to know about this form of antibiotic prophylaxis W ith 65% of U.S. oph- thalmologists who participated in the 2017 ASCRS Clinical Survey saying topical drops characterize their intraopera- tive antibiotic prophylaxis protocol, young physicians might wonder whether they should follow suit or select intracameral antibiotics. Nick Mamalis, MD, professor of ophthalmology and director of ocular pathology, Moran Eye Center, University of Utah, Salt Lake City, said he thinks residents, fellows, and those early in practice are good candidates for using intracameral antibiotics. "Especially in a setting of a teaching hospital or training en- vironment, I think it is even more important to consider the possibil- ity of intracameral antibiotics," Dr. Mamalis said, reasoning reduced risk of infection. There have been studies around the world, Dr. Mamalis continued, that show the incidence of endoph- thalmitis, although low with topical antibiotics, is even lower with intracameral antibiotics. Research that compared more than 315,000 cataract surgery procedures from 2005–2012 in the Kaiser Permanen- te, California group, for example, found that "intracameral antibiotic use was more effective than topical agent alone" in preventing endoph- thalmitis. 1 Retrospective analysis of a clinical registry from the Aravind Eye Care System in India (more than 617,000 cataract surgeries performed in a 29-month period) found that intracameral moxifloxacin reduced the endophthalmitis rate by 3.5-fold in manual small incision cataract surgery and phacoemulsification cataract surgery cases compared to eyes that did not receive intracam- eral moxifloxacin (all eyes during the study period received topical ofloxacin pre- and postop). 2 Then there is the 2006 landmark Europe- an Society of Cataract & Refractive Surgeons (ESCRS) multicenter study that found the incidence of endoph- thalmitis in treatment groups that did not receive intracameral cefurox- ime was five times higher than those that did. 3 Despite these studies and oth- ers like it, an overview of current practice patterns around the world showed that the use of intracameral antibiotics is not universally accept- ed. 4 As previously stated, according to data from the 2017 ASCRS Clini- cal Survey, 65% of U.S. ophthalmol- ogists report using topical antibiotics (slightly more than 40% use intra- cameral injections) as their intraop- erative antibiotic protocol; 56% of non-U.S. ophthalmologists perform antibiotic prophylaxis via intracam- eral injection. (Respondents to the survey were able to select all options that applied to them, which also included infusion through balanced salt solution, tranzonular/intravit- real injection, and subconjunctival injection.) One possible reason for the reduced acceptance of intracam- eral antibiotics in the U.S. is the lack of an approved, single-use antibiotic for intracameral use. For those using intracamerals, 75% use moxifloxacin or cefuroxime (43% moxifloxacin and 32% cefuroxime). Cefuroxime was more popular in Europe (51% of non-U.S. respondents using intraca- meral antibiotics selected this drug), likely because there is an approved, prepared, single-use formulation. How the pros practice Dr. Mamalis said when he performs cataract surgery at a Veteran's Affairs hospital, he uses intracameral moxi- floxacin, drawing up 0.1 mL directly out of a new, unopened bottle of Vig- amox (Novartis, Basel, Switzerland). When he performs cataract surgery at the University of Utah, however, the university's pharmacy makes preservative-free moxifloxacin under sterile conditions for intraca- meral use. Russell Swan, MD, Vance Thompson Vision, Sioux Falls, South Dakota, has experience with differ- ent types of intracameral antibiotics. Currently, he uses dexamethasone/ moxifloxacin/ketorolac (Imprimis Pharmaceuticals, San Diego) intra- camerally and sub-Tenon's for a steroid/anti-inflammatory effect. Even with an intraocular injec- tion of an antibiotic and steroid, Dr. Swan said he still prescribes one drop per day. Depending on the patient's insurance or preference, he will prescribe a daily NSAID or the Considering intracameral antibiotics T he use of intracameral antibiotic prophylaxis came into the spotlight a decade ago when the ESCRS prospective randomized multicenter trial demonstrated a five-fold drop in endophthalmitis rates in patients receiving intracameral cefuroxime (1mg/0.1 ml). Since then, there have been many large retrospective cohort studies that have likewise demonstrat- ed a lower incidence of postoperative endophthalmitis in patients receiving various intracam- eral antibiotics. While the rate of U.S. surgeons using intracameral antibiotics has increased from 14% in 2007 to about 41% in 2017, according to the latest ASCRS Clinical Survey data, this growth is not commensurate with the preponderance of data or the practice patterns of our European counterparts. Clearly, barriers remain that limit universal adoption in the U.S. Some surgeons not using intracameral antibiotics cite an already very low rate of endophthalmitis (0.04–0.3%), while others are quick to highlight that, with the exception of the ESCRS study, the existing evidence is retrospective. Beyond these perspectives, however, are two larger issues: (1) There is not an FDA-approved antibiotic, and as a result there is not a uniform/commercially produced, single-use, sterile product in the U.S.; and (2) there are safety concerns regarding medication toxicity and compounding errors. Currently, in order to use intracameral antibiotics, one must either tackle the legal and logistical challenges of preparing a medication that is packaged and approved for topical application for use in the eye, or a U.S. surgeon must rely on a compounding pharmacy to prepare such medications. Despite 503B status designation standards for certain compounding pharmacies, there will always be some level of risk of dilution error and contamination given such a production model. Concentra- tion errors with intracameral cefuroxime have been associated with toxic anterior segment syndrome (TASS) and retinal toxicity. Compared to cefuroxime, vancomycin and moxifloxacin are technically more easily compounded. However, as discussed herein there is concern for association between intracameral vancomycin and HORV, which has curtailed its use in the U.S. Thus far, intracameral moxifloxacin seems to be relatively safe at standard concentrations ranging from 0.25% to 0.5%. With these considerations in mind, U.S. surgeons face a dilemma: Is the risk of inject- ing antibiotic into every eye worth the reduction in risk of postoperative endophthalmitis? In this month's "YES connect" column Nick Mamalis, MD, Russell Swan, MD, and Michael Greenwood, MD, discuss their rationale for choosing to use intracameral antibiotics as well as techniques for integration of these medications into daily practice. While many surgeons have adopted a similar approach to that described by Drs. Mamalis, Swan, and Greenwood, the reality is that intracameral antibiotics are unlikely to become ubiquitous until there is an FDA-approved, single-use, commercially available product. Without a foreseeable economic return, there has not been industry incentive to push approval, which is a great detriment to our patients. As discussed in the article, the ASCRS Research Council has thankfully begun development of a prospective research trial, which will hopefully lead to FDA approval and, ultimately, a product that all surgeons can feel confident using. Zachary Zavodni, MD, YES connect co-editor From the 2017 ASCRS Clinical Survey • Nearly three-quarters of YES respondents (73%) use topical antibiotics. • 41% of YES respondents use intracameral injections. • Moxifloxacin (53%) and cefuroxime (36%) were listed as preferred injectable intraoperative antibiotics by YES respondents. • 25% of YES respondents said they plan to start using intracameral antibiotics within the next 12 months, while 39% said they do not plan on initiating this practice during that timeframe.

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