Eyeworld

EW CATARACT/IOL 56 March 2011 by Vanessa Caceres EyeWorld Contributing Editor Targeting TASS Questionnaires, site visits reveal TASS causes R esearchers recently gleaned a better under- standing of the causes of toxic anterior segment syndrome (TASS). A re- port in the July 2010 issue of the Journal of Cataract & Refractive Sur- gery (JCRS) reported on the results from 77 questionnaires and 54 site visits, all from surgical centers that have reported cases of TASS since 2006. TASS causes a sterile inflamma- tory reaction and typically presents 12 hours to 2 days post-op. Limbus- to-limbus corneal edema, damage to the endothelial cell layer, a break- down in the blood-aqueous barrier, iris damage, and glaucoma second- ary to trabecular meshwork damage are all associated with TASS. Although topical steroids can treat TASS, in severe cases, perma- nent corneal edema, glaucoma, and other chronic inflammation can occur. TASS received a great deal of at- tention within ophthalmology in 2006 when a number of cases were reported and again when the syn- drome was associated with a particu- lar irrigating solution. "We wanted to point out that TASS still occurs," said study co-investigator Nick Mamalis, M.D., professor of oph- thalmology, John A. Moran Eye Cen- ter, ophthalmology and visual sciences department, University of Utah, Salt Lake City. Dr. Mamalis is co-chair of the ASCRS TASS Task Force as well. "When there is an out- break, people hear a lot about it. When things quiet down to base- line, people tend to forget about it. It's important to bring it to the fore- front," he said. In addition to the goal of avoid- ing TASS outbreaks, another reason to bring TASS to the forefront is be- cause its causes, as shown by the study results, are due to some com- mon errors, said Henry F. Edelhauser, Ph.D., professor of ophthalmology and director of ophthalmic research, Emory School of Medicine, Atlanta. "Cataract surgery is to some ex- tent routine. A lot of times, it's a high-volume surgery, and things are moving quickly," said Dr. Edelhauser, who is also co-chair of the ASCRS TASS Task Force. "It takes a lot to clean instruments, and sometimes there's not adequate time." Study details Study investigators, led by Carolee M. Cutler Peck, M.D., John A. Moran Eye Center, retrospectively analyzed 77 questionnaires that were completed on the ASCRS web- site. The goal of the questionnaires was to facilitate the reporting of TASS cases. The questionnaires ad- dressed instrument cleaning, repro- cessing practices, surgical protocols, and techniques for cleaning instru- ments. Ultimately, 68 questionnaires were included in the study. The cen- ters that responded were mostly in the U.S. (n=62), although there was one center each from Argentina, Brazil, Italy, Mexico, Spain, and Ro- mania. The reporting centers had performed 50,114 cataract surgeries and had reported 909 cases of TASS. The study also took into ac- count site visits to certain practices that had experienced TASS out- breaks. "From January 1, 2006, to date, the 54 centers visited by a TASS Task Force member reported 367 cases of TASS in 143,919 procedures performed; 61% of them occurred in 2006," the investigators wrote. The number one factor associ- ated with TASS was inadequate flushing of the phaco and irriga- tion/aspiration (I/A) handpieces after surgery. "Of the 68 centers that filled out questionnaires, more than 60% used less than the recom- mended 120 cc per port (range 2 to 100 cc per port)," investigators wrote. "Other factors included oc- cluded I/A tips during surgery, a symptom of inadequate flushing." Of the centers for which site vis- its were conducted, 48% had inade- quate flushing of phaco and I/A pieces and cannulated equipment. The study found that 43% of centers for which site visits were conducted had used enzymatic cleaners and detergents, 37% had used reusable cannulas, and 35% had inadequate or no manual clean- ing of instruments; 28% had used preserved epinephrine in the ante- rior chamber. "Cleaned instruments were often left on towels that were not lint-free, and many centers did not train personnel regarding TASS and proper cleaning practices," study in- vestigators reported. A number of other items were frequently reported at centers with TASS cases, including use of tap water with no sterile water final rinse, reuse of single-use items, and poor instrument maintenance. The cleaning issues associated with TASS do not surprise Dr. Edelhauser. "These instruments have small holes and bores, and every- thing in cataract surgery swims in viscoelastic. The viscoelastic is sticky and difficult to clean out." Dr. Edelhauser knows a nurse who likens viscoelastic in instruments to a child spilling maple syrup on the kitchen table—in other words, it's not going to get cleaned off easily. Combine the difficulty of clean- ing these instruments with the hec- tic pace at high-volume centers, and the chance for a problem like TASS to occur increases, he said. The study also tracked medica- tions given intracamerally or added to a balanced salt solution that be- came another potential source of TASS. Twenty-five percent of centers that responded to the questionnaire reported adding antibiotic agents to the balanced salt solution irrigant; 21% had used intracameral antibi- otic agents. "The use of antibiotic agents may be associated with toxic- ity when they are included in ante- rior chamber irrigant and when injected intracamerally at the end of a case," investigators wrote. Al- though some intracameral antibi- otics have been studied as prophylaxis against infection, inves- tigators still view their use with cau- tion. Preventing TASS Based on the study results, investiga- tors gave a number of recommenda- tions to ophthalmic surgical centers. Here are some of them: 1. Follow instrument manu- facturers' cleaning instructions to the letter, Dr. Edelhauser said. This can make a big difference in pre- venting TASS. As easy as that may sound, many tend to read the in- structions only when they en- counter problems, he explained. By following manufacturers' in- structions, surgical centers can de- crease infection risk and avoid problems identified due to the use of enzymatic detergents, ultrasonic baths, and other common cleaning methods. Handpieces should be wiped off with a lint-free cloth and immedi- ately immersed in sterile water until they are flushed, the study investiga- tors advised. This was not done at 89% of centers visited, but by doing so you can remove residual vis- coelastic and debris from drying within the handpiece and tips. 2. Keep a number of surgical trays on hand. Thorough instru- ment cleaning may not be possible in the middle of a busy schedule, so TASS 1-day post-op Source: Simon Holland, M.D.

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