NOV 2012

EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.

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62 EW CORNEA November 2012 Acanthamoeba treatment patterns on display by Maxine Lipner Senior EyeWorld Contributing Writer What cornea specialists say they are doing to treat Acanthamoeba W hen it comes to treat- ing Acanthamoeba keratitis, 62.2% of respondents in a Cornea Society survey reported that at least some of the time they considered using a corticosteroid in these patients, according to Catherine E. Oldenburg, M.P.H., study coordina- tor and epidemiologist, University of California, San Francisco. The results, published in the December 2011 issue of Cornea, highlighted myriad practice patterns for treating this sometimes intractable infection most commonly associated with those who wear contact lenses. Investigators noticed that there seemed to be divergent ways of deal- ing with Acanthamoeba keratitis due to a lack of good evidence of what treatment approach worked best. "We were curious to see what people around the country and around the world were doing," said Jeremy D. Keenan, M.D., assistant professor, University of California. Participants, all of whom were members of the Cornea Society, took part in an online survey in which they were given a series of questions on go-to, ancillary, and surgical treatments and how these fit into their own personal algorithms to combat Acanthamoeba keratitis. Combination versus monotherapy Investigators found that the major- ity of people use combination therapy when dealing with such an infection. "Over 97% had used combination therapy in the past, whereas only 47% had used monotherapy," Dr. Keenan said. "People are definitely using combi- nation therapy, although some have tried monotherapy." He thinks that the reasons why people would use combination therapy instead of monotherapy are an indication of the fact that many don't believe that use of a single drug would be suffi- cient. "About 55% didn't think that it was effective," Dr. Keenan said. "Twenty-two percent thought that there was not enough evidence to support using monotherapy." When asked why some used monotherapy instead of a combina- tion approach, participants cited a variety of factors. "About 23% said that it was due to poor compliance, 22% said that it was because they didn't have access to the medica- tions for some reason, and 20% said that it was because of cost," Dr. Keenan said. Elmer Y. Tu, M.D., associate professor of clinical ophthalmology, and director, Cornea Service, University of Illinois, Eye and Ear Limbal continued from page 61 redness, light sensitivity, or some decreased vision. Complications and treatment LSCD can heal on its own; however, sometimes a more rigorous treat- ment plan, like surgery, is necessary. "The treatment for this can be as simple as taking [patients] out of the contact lenses and lubricating," Dr. Jeng said. "Sometimes we'll throw in topical steroids." He said in more advanced cases, surgery might be the answer, but this requires a certain degree of caution because LSCD in one eye usually indicates a higher possibility of a patient having it in the other eye as well, so taking cells to trans- plant from one eye to the other could lead to stem cell failure in the "good" eye. "If you knock out enough of your stem cells, then you can have chronic, non-healing epithelial defects, end up with scarring and ul- timately vision loss," Dr. Jeng said. Dr. Djalilian said some of the other complications that can arise from LSCD include "secondary stromal scarring, loss of vision, and permanent loss of the limbal stem cells." Dr. Djalilian said in addition to recommending patients stop wear- ing contact lenses, it is important to "optimize the tear film with the use of artificial tears, anti-inflammatory therapy, punctal occlusion, as well as treatment of associated meibo- mian gland disease." He said this treatment aids in reversing LSCD and its symptoms. Dr. Djalilian indicated that patients with LSCD could be candidates for refractive surgery, but may "require extra vigilance in pre- and post-op care." Similarly, Dr. Chan stressed that surgery is an option for those with LSCD, but a degree of caution is required. "Carefully selected patients with mild limbal stem cell defi- ciency that is stable and with an ocular surface that has been optimized may be candidates for laser vision correction," she said. However, patients also need to be aware of the difficulties that may come with the healing process and that some surgeries may further aggravate the LSCD. EW Editors' note: The physicians have no financial interests related to this article. Contact information: Chan: 416-960-5007, clarachanmd@gmail.com Djalilian: 312-996-8937, ali.djalilian@gmail.com Jeng: 415-206-8304, JengB@vision.ucsf.edu While single drug therapy is effective for treating Acathamoeba keratitis, the majority of practitioners use a combination approach Source: Elmer Y. Tu, M.D. Infirmary, Chicago, pointed out that there is some hard evidence, albeit limited, that monotherapy is effec- tive. "There is only one good study in the literature right now looking at the efficacy of these drugs, and they found that single drug therapy was effective for the vast majority of cases," Dr. Tu said. "But people still add a second or third agent in some cases as part of their initial treat- ment." Steroid prevalence Use of steroids in these patients is another area of contention. "In other infectious disorders, corticos- teroids are usually frowned upon, although that's changing a bit in bacterial keratitis," Dr. Tu said. Investigators found steroid use relatively prevalent. "About half said that they used steroids sometimes, and about 10% said that they used them most of the time," Ms. Oldenburg said. "The rest of the respondents said that they never used steroids." Most of the time, use was linked to inflammation. "Of the respondents who used steroids, about half of them said that they would use them in the setting of persistent inflammation to try to get inflammation down," Ms. Oldenburg said. "The remainder said that they do so when they're confident that the infection has been cured." continued on page 64

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