EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/78710
36 EW FEATURE February 2011 Perioperative pharmacology May 2012 Update on antibiotics: No clear-cut regimen yet by Jena Passut EyeWorld Staff Writer AT A GLANCE • For patients with significant cataracts, if Fuchs' dystrophy is severe enough with signs of corneal edema, a combination approach may be beneficial • If a Fuchs' patient has a significant cataract, there is often no advan- tage to leaving this behind since endothelial cell loss will inevitably be greater with two procedures • The combination procedure can be technically easier for the experi- enced surgeon since there is less space to maneuver in the phakic eye • For a beginning surgeon, however, allowing the lens implant to fibrose in the eye for a month or so may make the procedure easier • Outcomes are usually contingent on the DMEK portion of the procedure • Using thinner tissue ultimately provides better visual acuity W hen it comes to the role of pre- and post- op antibiotics in oph- thalmic surgical prophylaxis, one thing remains certain: There are no clear- cut answers on how to proceed, and controversy remains about what works best to reduce the risk of post-surgical endophthalmitis. "In part, it has been a bit of a moving target as procedures and techniques change," said Anesthesia continued from page 35 Dr. Arbisser's protocol includes 1 mg midazolam (range 0.5-2 mg) administered by her anesthesiologist. If the patient is tense and squeezes lids, "then we give 125 mg Alfenta [alfentanil, Akorn, Lake Forest, Ill.]," she said, noting the drug is diluted eight times making its final concen- tration 2 cc (125 mg), "or else vol- ume is too small to push without having to follow with saline." She re- serves using Alfenta intraoperatively for patients who feel pressure, and if that doesn't seem to work, she adds 10 mg of propofol mixed in with a second dose of Alfenta in the same syringe (attributing the protocol to Sang Sapthavie, M.D.). "It's a fine line between giving the patients enough sedative so they're not anxious and too much causing them to fall asleep, but our goal is to walk that fine line," she said. Pearls Keeping the patient alert but com- fortable and addressing any pain as soon as possible is the key to success- ful cataract surgery, Dr. Arbisser said. "The moment patients feel any pain their brains are going to start looking for that pain," she said. "By letting them know and empowering patients ahead of time to alert us when they feel something and we will address it right then" helps to keep patients' trust in the surgeon— and the surgery. She also advises using a speculum that won't stretch the lids to the point of discomfort. Regarding time(s) of dosing, lidocaine "lasts about 18 minutes, compared to tetracaine, which lasts about 45," Dr. Myers said. "So if you have to redose intraoperatively with lidocaine, there's no harm in doing so." Regardless of what anesthesia routine surgeons use, continual communication with the patient during the surgical procedure will help the procedure go smoothly, Dr. Arbisser said. EW Reference 1. Shimada H, Arai S, Nakashizuka H, Hatorri T, Yuzawa M. Reduction of anterior chamber contamination rate after cataract surgery by intraoperative surface irrigation with 0.25% povidone-iodine. Am J Ophthalmol. 2011 Jan;151(1):11-17.e1. Epub 2010 Oct 20. Editors' note: Drs. Arbisser, Arnold, and Myers have no financial interests related to their comments. Dr. Sikder has financial interests with Allergan (Irvine, Calif.). Contact information Arbisser: 563-323-2020, drlisa@arbisser.com Arnold: 563-323-2020, prisarnold@gmail.com Myers: wmyers@northwestern.edu Sikder: 520-465-0390, shameemasikder@gmail.com Dr. Arshinoff injects moxifloxacin intracamerally to help keep endophthalmitis at bay Source: Steve A. Arshinoff, M.D. Terrence P. O'Brien, M.D., professor of ophthalmology, Bascom Palmer Eye Institute, Miller School of Medi- cine, University of Miami. "Despite all efforts pre-operatively to prevent contamination and inoculation of the eye with organisms, they can be recovered from the aqueous humor a surprisingly high percentage of the time, maybe 5-30%. You may have organisms that can be recovered at the conclusion of the case even in a procedure that has been uncompli- cated." The question then becomes what to do about potential organ- isms that may enter the eye even with the perfect surgery being per- formed. "In general, true surgical pro- phylaxis is supposed to be not using the final greatest guns, but [using] the most basic good coverage," said Lisa B. Arbisser, M.D., adjunct asso- ciate professor, John A. Moran Eye Center, University of Utah, Salt Lake City. "Ophthalmologists are unable to pay attention to the dictates of normal surgical prophylaxis because it requires having the minimum in- hibitory concentration (MIC) for the appropriate organism at a high enough level prior to making an in- cision and keeping it at that level throughout the surgery until after the incision is closed." The MIC is the minimum amount of the antibiotic that is needed to inhibit bacterial growth, according to Francis S. Mah, M.D., medical director, Charles T. Camp- bell Ophthalmic Microbiology Labo- ratory, University of Pittsburgh School of Medicine. Dr. Mah said many questions remain surrounding the use of an- tibiotics for prophylaxis in cataract surgery. "Even though we think we know a lot, there's still a lot that we don't know," he said. "We don't know what's truly appropriate as far as dosing. There are some people who use topical antibiotics once or twice a day pre-operatively. Some people are injecting intracamerally." "As far as the true efficacy of these drops, we don't know if these drugs are doing that much or if it's our smaller incisions that are leading to fewer endophthalmitis infections. No one can really separate that out