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E W CORNEA 96 March 2014 perborate rapidly decomposes into hydrogen peroxide, which ulti- mately breaks down into salt and w ater. GenTeal (Novartis, Basel, Switzerland) is one artificial tear that contains sodium perborate, Dr. de Luise said. Another oxidative preservative, known as stabilized oxychloro com- plex (SOC), has good antimicrobial activity and is more apt to kill fungi than some of the others, Dr. de Luise s aid. "It's safer than the chemical preservatives, even when dosed more than four times a day," he said. He cited bottled Refresh Tears (Allergan, Irvine, Calif.) as an example of an SOC-containing artificial tear. "I consider eye drops that contain oxidative preservatives several notches better than those w ith chemical preservatives, but they are still eye drops with preserv- atives," Dr. de Luise said. Meanwhile, anything on the store shelves that has the letters "PF" is preservative free and comes in sin- gle-dose vials. Current recommendations In Dr. de Luise's view, artificial tears with chemical preservatives are the most worrisome choices. Those with vanishing preservatives are much better, and the preferred strategy would be the use of preservative-free artificial tears. When prescribing preservative- free tears, it is important to describe for patients exactly the type of pack- aging for which to look, he said. "Patients tend to get confused. They will end up buying the bottle if you don't tell them to look for the vial." To avoid confusion, many practices give patients sheets with photo- graphs of the preservative-free a rtificial tear boxes that are recom- mended. John D. Sheppard, MD, profes- sor of ophthalmology, microbiology, and molecular biology, Eastern Vir- ginia Medical School, Norfolk, Va., likewise views preservatives in tears as detrimental for dry eye patients. "Preservatives are fine for short-term u se," Dr. Sheppard said. He pointed to antibiotic drops, which may be taken for a brief period, as a case where preservatives are not only non-problematic, but may provide a synergistic antimicrobial effect. But he stressed that in dry eye and glau- coma, use of chronic preservatives has a cumulative effect. H e doesn't recommend any tears with chemical preservatives, al- though he does sometimes suggest those with the vanishing alternative, which change their character from antimicrobial to benign tear elec- trolytes. "I don't see any reason when we have these good products on the market to use a tear with chemical preservatives in it," Dr. Sheppard said. For routine patients he relies on tears with vanishing preservatives. Even younger patients who would be more resistant to issues of surface damage are often at risk with preser- vatives since many wear contact lenses, which may prolong preserva- tive contact time with the ocular surface. In addition to the eye being relatively hypoxic in such cases, the contact lens itself may compound the problem. "The tears and there- fore the preservatives will become trapped underneath the contact lens and you've got a physiologically sustained release delivery situation," Dr. Sheppard said. When it comes to more ad- vanced dry eye cases, Dr. Sheppard advises patients to use completely p reservative-free tears only. Christopher J. Rapuano, MD, chief of the cornea service, Wills Eye Hospital, Philadelphia, agreed that those with particularly compromised ocular surfaces should avoid preserv- atives. "The more compromised the ocular surface, whether it's damage from dry eye, blepharitis, chemical b urns, or whatever, the less it toler- ates preservatives," Dr. Rapuano said. Also, he said it's important to keep in mind the total amount of preservatives that get into the eye each day. If patients' eyes are pretty healthy and they're using drops just a few times a day, this is not a big problem, he observed. "But if their eyes are somewhat compromised and they're on tears three or four times a day it may become a prob- lem," Dr. Rapuano said. "If their eyes are somewhat compromised and they're on tears 10 times a day, that is potentially a big problem." In addition, he said it's not just the amount of preserved tears to be con- cerned about but also factors such as preserved glaucoma medications, which are also taken chronically. "If they're on three glaucoma medica- tions and each of those medications has a preservative in it, then you've got to add that to the amount of preservatives that they're getting with the tears," Dr. Rapuano said. He switches such patients to preser- vative-free tears and finds that their eyes often do much better. "The downside of preservative- free tears is that they're more expen- sive and they're less convenient," he said. With this in mind, Dr. Rapuano tells patients when possible to use one vial for the entire day instead of throwing the vial away after one use. Meanwhile, not everyone thinks that the preservative-free approach is necessary. Robert A. Latkany, MD, associate professor, New York Eye and Ear Infirmary, New York, views these as essentially hype. "For the last decade or so, there has been a lot of talk on artificial tears, and I am now fairly convinced that there is not a whole lot of merit to the claim that preservatives are damag- ing to the surface of the eye," Dr. Latkany said. In his dry eye practice, he has had many patients who have had reactions to the preservative-free tears. Dr. Latkany thinks this may be some sort of allergic reaction. He has not, however, seen any- one who has had a reaction to the preservative itself. "How many peo- p le have I seen in the last 15 years who had what appeared to be a reac- tion to the preservative found in the artificial tear drop—zero," he said. "It's a sensitive population—sensi- tive population patients have reac- tions to chemicals you put in their eyes. It doesn't necessarily mean it's the BAK." I t's very expensive to use preser- vative-free drops. "It could be hun- dreds of dollars a year for patients over the price of a preserved bottle," Dr. Latkany said. His goal is to get patients off of tears altogether. "I'll dig deep and try to find out where this inflammation is coming from," he said. Dr. de Luise acknowledges the added expense but views the preser- vative-free option as necessary for all but the very mild dry eye patient. "There are no magic bullets—dry eye disease is a diagnosis that is often made in a patient's 30s or 40s that is chronic and may get worse as the patient gets older," he said. He urged practitioners to take the time and talk to patients about this. "Say, 'This is a lifetime disease, you're not going to go blind, but I recommend that you use single-dose drops as op- posed to those with preservatives,'" Dr. de Luise said. "They'll spend a bit more but they'll be better served by medicines and drops that are more soothing to the surface." EW Editors' note: Dr. de Luise has no financial interests related to this article. Dr. Latkany has no financial interests related to this article. Dr. Sheppard has financial interests with AbbVie (North Chicago), Alcon, Allergan, Bausch + Lomb (Rochester, N.Y.), TearScience (Morrisville, N.C.), TearLab (San Diego), and Nicox (Sophia Antipolis, France). Dr. Rapuano has financial interests with Allergan, Bausch + Lomb, BioTissue (Doral, Fla.), Nicox, TearLab, and TearScience. Contact information de Luise: vdeluisemd@gmail.com Latkany: relief@dryeyedoctor.com Sheppard: docshep@hotmail.com Rapuano: cjrapuano@willseye.org A cleared-eye continued from page 94 88-107 Cornea_EW March 2014-DL2_Layout 1 3/6/14 3:47 PM Page 96