EyeWorld India June 2017 Issue

June 2017 EWAP SECONDARY FEATURE 27 moxifloxacin.” He added that “none of them can be treated as ideal for IC prophylaxis.” Dr. Mamalis noted that multiple studies published since the original ESCRS endophthalmitis study using cefuroxime have shown it is effective in preventing postop endophthalmitis. Cefuroxime has been approved by European regulators and is available for easy mixing for use in intracameral injections. However, Dr. Grzybowski noted that “MRS, penicillin-resistant Streptococcus pneumoniae, and Pseudomonas spp. are resistant to cefuroxime” and the increase in endophthalmitic cases caused by resistant bacteria was reported in Europe. 5 “Cefuroxime must be mixed by compounding pharmacies or mixed by the operating room staff for U.S. surgeons who wish to use it,” said Dr. Mamalis, who is chair of the ASCRS Toxic Anterior Segment Syndrome (TASS) Task Force. Among surgeons who have used moxifloxacin, the greatest experience has been with Vigamox (moxifloxacin, Alcon, Fort Worth, Texas), which is preservative- free, and used for injection intracamerally at the conclusion of the surgery—either diluted 50- 50 with balanced salt solution or undiluted. “We’ve actually run into problems with TASS occurring in intracameral antibiotic when the antibiotic is mixed at an incorrect dosage,” Dr. Mamalis said. “When you are trying to mix, especially the cefuroxime, that’s a multistep procedure, and if that is done wrong in the operating room you can end up getting doses 10 times the recommended dose and that can cause toxicity.” Toxicity problems also have stemmed from mistaken use by compounding pharmacies of non- preservative-free moxifloxacin for intracameral injections. “So, the features that we are looking for is that the compounding pharmacy or whoever is mixing these is extremely accurate and that you get the proper dosage that you need to inject intracamerally,” Dr. Mamalis said. Vancomycin has been used at several large surgery centers for 20 years, but recent evidence has emerged that it can be associated with postop hemorrhagic occlusive retinal vasculitis (HORV). “Although this is extremely rare, this is a very serious, devastating condition and as a result, surgeons have had to reconsider in the use of intracameral vancomycin for the prevention of endophthalmitis,” Dr. Mamalis said. The problems that have arisen from intracameral use of some antibiotics and concerns over increasing antibiotic resistance led Dr. Grzybowski to urge moving away from antibiotic-based endophthalmitis prophylaxis to antisepsis-based endophthalmitis prophylaxis—mostly with povidone–iodine (PVI). “It was recently shown that PVI can be safely and effectively used in the treatment of keratitis and conjunctivitis,” Dr. Grzybowski said, adding that the recent European study by Freiberg et al. based on 134,701 intravitreal injections reported an exceptionally low rate of endophthalmitis (0.0074% per injection with no antibiotics and only PVI used in the peri-injection period). 6 Dr. Grzybowski noted that in the U.S., IC antibiotics are given supplementary to topical antibiotics causing an increase in unnecessary consumption of antibiotics. Whereas, in many European countries, topical antibiotics are eliminated with the use of IC antibiotics. Next steps Among the newer initiatives focused on intracameral antibiotic use is that of the ASCRS Research Council, which is putting together a large group of ophthalmologists and ophthalmic centers that can perform large-scale studies. “And one of the first topics that this council is going to look into is trying to put together a large study to look at intracameral antibiotics with the idea that we would get enough patents in the study to show that there is a difference that would be significant enough to allow submission to the FDA for an eventual approval of intracameral antibiotics for prevention of endophthalmitis,” Dr. Mamalis said. Pharmaceutical companies could use such research to seek FDA approval. “And that would allow the manufacturer of single-use doses of intracameral antibiotics that surgeons can use in an approved manner directly from the company,” Dr. Mamalis said. “That’s going to be a big step going in that direction.” ASCRS also is checking whether the FDA would consider data from previous studies, such as the ESCRS endophthalmitis study, as evidence of the efficacy of the antibiotics. “The ASCRS is being proactive to try to set up the study, which will hopefully allow the approval of these agents to be used in the U.S. in a similar way to how they are used in Europe,” Dr. Mamalis said. EWAP References 1. Barry P, et al. ESCRS study of prophylaxis of postoperative endophthalmitis after cataract surgery: Preliminary report of principal results from a European multicenter study. J Cataract Refract Surg . 2006;32:407–10. 2. Braga-Mele R, et al. Intracameral antibiotics: Safety, efficacy, and preparation. http://www.ascrs.org/ sites/default/files/resources/JCRS_ December_2014.pdf 3. Shorstein NH, et al. Decreased postoperative endophthalmitis rate after institution of intracameral antibiotics in a Northern California eye department. J Cataract Refract Surg . 2013;39:8–14. 4. Haripriya A, Chang DF, Namburar S, Smita A, Ravindran RD. Efficacy of intracameral moxifloxacin endophthalmitis prophylaxis at Aravind Eye Hospital. Ophthalmology . 2016;123:302–8. 5. Grzybowski A, Brona P, Kim S. Microbial flora and resistance in ophthalmology: A review. Graefe’s Archive for Clinical and Experimental Ophthalmology 2017 DOI 10.1007/s00417-017-3608-y. 6. Freiberg FJ, et al. Low endophthalmitis rates after intravitreal anti-vascular endothelial growth factor injections in an operation room. A Retrospective Multicenter Study. Retina . 2017 Jan 17. Editors’ note: The surgeons interviewed for this article have no financial interests related to their comments. Contact information Grzybowski: ae.grzybowski@gmail.com Henderson: bahenderson@eyeboston.com Mamalis: nick.mamalis@hsc.utah.edu