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67 January 2015 EW MEETING REPORTER "Bug OFF: Infectious Keratitis Risk Factors, Prevention, and Manage- ment." The society's highest award was presented to Francis W. Price Jr., MD, Indianapolis, who delivered his Asia Cornea Foundation Medalist Lecture on "Glaucoma and Trans- plants." The ceremony concluded with the ACS Council members taking to the stage holding glow stick wands, which they used to symbolically light an LED globe, officially opening the meeting. The yin and yang of corneal transplants and glaucoma In his Asia Cornea Foundation Medalist Lecture, Francis W. Price Jr., MD, Indianapolis, took a philo- sophical slant to considerations of glaucoma and corneal transplants, adopting the yin-yang symbol as the central image. Glaucoma and transplants, he said, are "bound together" even as they present "contrary forces." "If we work on one of them, we very often cause the other one to occur," he said. "This has been a big challenge with our corneal trans- plants, dealing with glaucoma." For instance, when treating pen- etrating keratoplasty (PK) patients, "we're trying to balance the use of topical corticosteroids compared to having rejections, and trying to find the right dosage without causing glaucoma, or we have glaucoma and try to not have rejections." What we do know, he said, is: 1) glaucoma surgery can cause corneal decompensation, and 2) corneal transplant surgery can cause glaucoma. "What's important is that tissue- specific corneal transplants help us better understand what glaucoma surgery does to the cornea," he said. "Corneal transplants may be the canary in the [coal] mine for filtra- tion surgery." Conversely, "the type of filtration surgery you use today is going to determine how busy corneal surgeons are going to be in the future." PK has a somewhat recipro- cal interaction with glaucoma: PK increases the risk of IOP elevation while glaucoma increases the risk of failure and reduces visual results in PK. PK also makes it difficult to monitor IOP, allowing glaucoma to worsen unnoticed. On the other hand, Descemet's stripping endothelial keratoplasty (DSEK) allows easy measurement of IOP. Preexisting glaucoma does not seem to significantly affect outcomes with DSEK, and DSEK can signifi- cantly improve vision in patients with glaucoma—although tube and trabeculectomy surgery is a signifi- cant risk factor for DSEK failure. Meanwhile, Descemet's mem- brane endothelial keratoplasty (DMEK) results in significantly fewer rejections than either PK or DSEK. This potentially allows reduction of glaucoma-inducing steroid use. The balance here is the risk of rejection against the risk of elevated IOP. In any case, Dr. Price said that "filters are bad for grafts," but if patients need filtration surgery, they should be told they need to have the filter or go blind—corneas can be replaced; optical nerves cannot. Dr. Price prefers the Alvarado technique for tube surgery. The technique produces a low profile for the tube. Glaucoma surgery, he said, should be performed when IOP cannot be controlled and there is danger of nerve damage. The sur- geon should select the least invasive technique. Geographic variations in infectious keratitis One of the major achievements of the ACS in terms of corneal research is the landmark Asia Cornea Society Infectious Keratitis Study (ACSIKS), a multicenter, prospective, observa- tional study involving 13 countries. In her Asia Cornea Foundation Lecture (Asia), Fung-Rong Hu, MD, Taipei, Taiwan, summarized some of the study's findings. According to data from ACSIKS, the most important risk factor for infectious keratitis in the region is trauma, accounting for 52.7% of cases, followed by contact lens use. The most common etiolog- ic agent is fungus, followed by gram-positive bacteria. There is, however, wide geo- graphic variation. Broadly speaking, trauma is the leading risk factor in developing countries, while contact lens use is the top risk in developed countries, trauma second. The microbiological profile of infectious keratitis varies even more significantly geographically. For instance, while fungus followed by gram-positive bacteria are most com- mon overall in the region, the most common microbiological etiology of infectious keratitis in Taiwan is gram-negative Pseudomonas aerugino- sa associated with contact lens wear. Among other things, the landmark study and the geographic variations it reveals highlight the importance of local epidemiological research. She added that molecular analysis and identification of various genotypes and subspecies are in- valuable in determining patterns of antibiotic treatment, resistance, and susceptibility. Alternative keratoplasty In one of the first scientific sessions of the meeting, ophthalmologists explored alternative approaches to keratoplasty. In China, where there is a severe shortage in corneal donation, Zhiqiang Pan, MD, Beijing, China, and his colleagues studied the "Clin- ical Potential of Pig Corneal Xeno- transplantation." The three obstacles are immunologic rejection, infection (zoonoses), and ethical dilemmas. Porcine organs, he said, have high genetic homology with human tissue. Pig corneas, in particular, have comparable diameters, optical power, and histology. The cornea is also avascular and aqueous humor factors can inhibit complement activation. View it now: ACS 2014 ... EWrePlay.org Terry Kim, MD, discusses applications of adhesives during cataract surgery and cornea surgery. continued on page 68

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