EyeWorld Asia-Pacific December 2012 Issue

48 EWAP PHARMA FOCUS December 2012 Homing in on top regimens W hile you want to make sure that all cataract patients receive excellent antibiotic coverage, certain high-risk cases require even more diligence. “Probably about 20% of our patients have some risk factor that we conventionally consider a risk factor for infection,” said Eric D. Donnenfeld, MD , co-chairman, Cornea, Nassau University Medical Center, East Meadow, NY, USA. “But the biggest risk factor is one that we weren’t aware of until last year, and that is age.” It has come to light that the older the patient, the greater the risk of colonization by methicillin- resistant Staph aureus (MRSA). “As a matter of fact, half of the patients Keeping infection at bay while dipping into the high-risk cataract pool by Maxine Lipner Senior EyeWorld Contributing Editor over age 80 will be colonized by methicillin-resistant Staph in their eyelid margin at the time of surgery, and these are patients who have no other known risk factors,” Dr. Donnenfeld said. How can practitioners best protect these and other high-risk patients? EyeWorld homed in on the regimens being touted by top practitioners. Keeping a lid on infection Besides age, Dr. Donnenfeld pegged factors such as vitreous loss and wound leaks as increasing risk, along with patient factors such as having diabetes or having worked in a hospital setting. Dr. Donnenfeld keeps his guard up in all cases. “I go into cataract surgery with the expectation that the patient is going to be at risk for infection, and I treat every patient that way,” he said. Dr. Donnenfeld advocates closely examining the patient’s lid margins pre-op since the lids are responsible for the organisms that cause endophthalmitis. “I think that the lid margins are under examined,” he said. If he has a patient with significant blepharitis, he will initially treat with hot compresses and omega-3 fish oil supplementation. In more aggressive cases he will add an antibiotic to the mix to rub into the lid margins. “For chronic meibomian gland dysfunction (MGD), I like topical azithromycin,” he said. For patients who have acute inflammation for whom he is worried about MRSA, he likes to use bacitracin ointment pre- op. In high-risk patients, to give added gram-positive coverage, he also will use bacitracin lid scrubs pre-op for a week, rubbed into the eyelid twice a day. For topical therapy, he will sometimes use Polytrim (trimethoprim sulfate and polymyxin B sulfate, Allergan, Irvine, Calif., USA) as well, which he finds has good MRSA coverage. Betting on besifloxacin At the time of the surgery Dr. Donnenfeld will routinely prophylax his patients with a topical antibiotic. He currently relies on besifloxacin (Besivance, Bausch + Lomb, B+L, Rochester, NY, USA). “The reason that I like besifloxacin is that of all the fluoroquinolones, it has the most activity against methicillin- resistant Staph,” Dr. Donnenfeld said. “There are no systemic analogues—you don’t have to worry about resistance with it.” In addition, he finds that the vehicle adheres to the lid margins, adding contact time there as well as to the tear surface. “It has been shown that one drop applied will achieve therapeutic doses for more than 24 hours,” Dr. Donnenfeld said. “I start that 3 days pre- operatively, and I continue it for 10 days postoperatively because the risk of endophthalmitis has been shown to be bimodal—a few days following surgery and then, due to late wound leaks, it can occur about 9 days postoperatively.” With this in mind, he continues the antibiotic topically for about 10 days. Dr. Donnenfeld augments this by using vancomycin intracamerally in all cataract cases. “That gives superlative gram-positive coverage, which is responsible for more than 90% of endophthalmitis,” he said. “That “The biggest risk factor for post-cataract infections such as this case of endophthalmitis caused by methicillin-resistant Staphylococcus aureus is age,” according to Dr. Donnenfeld. Source:Eric D. Donnenfeld, MD