Eyeworld

EW FEATURE 75 February 2011 February 2011 GLAUCOMA EX-PRESS device, which functions as a very small aperture with some re- sistance," Dr. Fechtner said. "We then provide additional resistance with the scleral flap, much as we do in trabeculectomy." Dr. Fechtner finds that the key differences for the surgeon and the patient are the relatively non-inva- siveness of the paracentesis and the small needle entry. The rest of the surgery is extraocular. "When per- forming the EX-PRESS procedure, it is unnecessary and in fact not really technically possible to do an iridec- tomy," Dr. Fechtner said. "This avoids many complications that might be associated with an iridec- tomy." It then becomes a question of determining for which patients the Ex-PRESS shunt may be preferable to a traditional trabeculectomy. Dr. Fechtner sees this issue of patient se- lection as a continuously evolving one for glaucoma surgeons. "We started out with Molteno tubes (IOP, Costa Mesa, Calif.) in our most com- plex eyes, and we now have a trab versus tube study suggesting that tubes might come very early in our surgical algorithm," he said. "Simi- larly, I think that as we gain experi- ence with the EX-PRESS and we accumulate knowledge about the re- sults, we will have a better idea of where it fits and what the best match is." In Dr. Fechtner's view there are a couple of types of patients for whom use of the EX-PRESS device is an excellent option. "The first obvi- ous place where the EX-PRESS would be a good match would be in a pa- tient who is at increased risk of bleeding," he said. A second type of patient that he often selects for the EX-PRESS is one in which there may be concern of vitreous behind the iris and that an iridectomy would re- lease this into the sclerostomy. Malik Y. Kahook, M.D., associ- ate professor, University of Col- orado, Denver, agreed that the EX-PRESS device is suitable for the same group of patients who would otherwise undergo traditional tra- beculectomy. However, he stressed that these are not the more extreme cases. "It's not the patient popula- tion that has failed two trabeculec- tomies for whom you then go on to a glaucoma drainage device like an Ahmed (New World Medical, Ran- cho Cucamonga, Calif.) or a Baerveldt (Abbott Medical Optics, AMO, Santa Ana, Calif.). It's also not the [early glaucoma] category, what we're calling the 'cataract plus,' where we would use the iStent and potentially the CyPass (Transcend Medical, Menlo Park, Calif.)," Dr. Kahook said. There are a few cases, however, in which Dr. Kahook finds the Ex- PRESS to be particularly helpful. "I use it for the monocular patient who needs quick visual recovery because in my hands, the EX-PRESS patient has quicker visual recovery than a traditional trabeculectomy patient," he said. "I also use it when I'm com- bining a cataract plus a trabeculec- tomy." He finds this to be a less traumatic procedure. "It's a quieter eye because I'm not doing a periph- eral iridectomy, I have more control of the anterior chamber, and I'm much less likely to get a shallow or flat anterior chamber post-opera- tively," Dr. Kahook said. He also tends to use the EX-PRESS in those patients who are on anticoagulants. This way, he can avoid an iridec- tomy and is much less likely to have a hyphema. Outcomes with the EX-PRESS are promising. Dr. Kahook recently conducted a study comparing the Ex-PRESS shunt to trabeculectomy, with results slated to come out in an upcoming issue of the American Jour- nal of Ophthalmology. He found that the device offers similar pressure lowering to traditional trabeculec- tomy. "We compared trabeculec- tomy to the EX-PRESS with 2 years of follow-up and we found that the IOP lowering was roughly compara- ble to that of trabeculectomy," he said. "They both essentially did the same and the pressure lowering was in the 11-13 mm Hg range for all pa- tients." Dr. Kahook also found that the speed of visual recovery with the EX-PRESS outstrips traditional tra- beculectomy. "We found that pa- tients recover onto their baseline visual acuity at 1 week after EX- PRESS versus 1 month for tra- beculectomy," he said. Dr. Kahook attributes this more rapid healing re- sponse to a combination of things. "There is much less surgical manipu- lation with the EX-PRESS so you're less likely to have corneal edema or uveitis post-operatively," he said. "You're also less likely to induce any astigmatism because it's minimally invasive." In addition, he pointed out that with the EX-PRESS the chances of complications such as hyphema are decreased, and patients are less likely to have very low in- traocular pressure in the early post- op days. Dr. Fechtner likewise has ob- served more rapid recovery with the EX-PRESS shunt, with pressure low- ering equivalent to trabeculectomy. "I do think that vision is better early on, and my clinical impression has been that it's easier to manage these post-operatively, as I have evolved into a better technique using the de- vice," Dr. Fechtner said. Overall, Dr. Fechtner sees both the iStent and the EX-PRESS shunt as moving glaucoma surgery for- ward. "I think that we should be very grateful as glaucoma surgeons to see industry and fellow surgeons innovating," he said. "We under- stand the problems with our current glaucoma procedures and yet we stick with them, waiting for some- thing to offer advantages—any small advantage to me is a major step for- ward in glaucoma surgery." EW Editors' note: Dr. Fechtner has financial interests with Alcon. Dr. Kahook has fi- nancial interests with Alcon and con- sults for the U.S. Food and Drug Administration. Dr. Lewis has financial interests with Alcon, Glaukos, iScience (Menlo Park, Calif.), and Sanofi-Avan- tis (Bridgewater, N.J.). Dr. Samuelson has financial interests with AMO, AcuMems (Menlo Park, Calif.), Alcon, Allergan (Irvine, Calif.), AqueSys (Irvine, Calif.), Endo Optiks (Little Sil- ver, N.J.), Glaukos, iScience, Ivantis (Irvine, Calif.), Pfizer (New York), QLT (Menlo Park, Calif.), and Santen (Napa, Calif.). Contact information Fechtner: 973-972-2030, fechtnrd@umdnj.edu Kahook: 720-848-2500, malik.kahook@gmail.com Lewis: 916-649-1515, rlewiseyemd@yahoo.com Samuelson: twsamuelson@mneye.com Standardized no-touch technique for DMEK R esearchers from the Netherlands described a stan- dardized, no-touch tech- nique for DMEK including all essential steps such as patient prep, graft im- plantation, orientation, unrolling, centering, fixa- tion, and positioning of a DMEK graft. "The procedure was designed to enable corneal surgeons to per- form DMEK in a con- trolled fashion while optimizing the visual out- come and minimizing the risk of graft detachment and endothelial cell dam- age," the researchers wrote. In the summary of the procedure, the physi- cians described the proper incision to make a 50% scleral-depth limbal incision, 3.0 mm wide, made and extended by lamellar dissection into the clear cornea with a slit knife. "With a 30-gauge cannula through a side port, the anterior chamber is completely filled with air," the researchers wrote. "Under air, the recipient Descemet's membrane is scored over 360 degrees using a reversed Sinskey hook prior to stripping off the membrane with the reversed Sinskey hook or a Descemet scraper." For the complete explanation of this no-touch technique, view the entire article at Archives of Ophthalmology (2011; 129, 88-94). 58-81 Feature_EW February 2011-DL2_Layout 1 2/4/11 2:31 PM Page 75

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