EyeWorld is the official news magazine of the American Society of Cataract & Refractive Surgery.
Issue link: https://digital.eyeworld.org/i/78719
September 2011 exposure to risks and, in my mind, that's not a trabeculectomy."The iStent (Glaukos Corp., Laguna Hills, Calif.; not commercially available in the U.S.) can be implanted after cataract surgery into Schlemm's canal. Positioning and getting a good view is the most important aspect of the surgery, Dr. Samuelson advised. "We're looking for landmarks, The use of aberrometry in the operating room, Dr. Packer said, has saved "me endless grief in first ex- plaining to patients that they need an enhancement, then performing that LASIK or PRK [photorefractive keratectomy] procedure with its ad- ditional list of complications, and then finally nursing the patient through that procedure. Many of these patients in this age group have dry eye, so LASIK or PRK are not the same slam-dunk procedures they are in a 20-something with 4 D of my- opia. Now I get great results the first time." Use IFIS protocol to treat patients, doctors advise All small pupil patients should be treated as if they have intraoperative floppy iris syndrome, according to two surgeons who spoke at the 2012 Hawaiian Eye meeting. "Everybody has the same potential, so we just take the patient history out of the equation," said Steven Dewey, M.D., Colorado Springs, Colo., who said that patients often forget to re- port certain medications they are taking that may result in intraopera- tive floppy iris syndrome (IFIS) com- plications. "There are so many etiologies out there, and the presentation is so variable that the screening became virtually impossible and much too time consuming. Everyone benefits from special precautions. … If IFIS is the most common intraoperative condition placing your results at risk, is it better to react to this or to try and prevent it to begin with?" Intracameral dilation that is di- rectly delivered to the target tissue is easy, fast, and convenient, Dr. Dewey said. Dr. Dewey said he has gone as far as adding IC tropicamide into the epinephrine solution. "I do it at the beginning of the case. It doesn't slow a thing down," he said. Mitchell P. Weikert, M.D., assistant professor of ophthalmology, Cullen Eye Institute, Baylor College of Med- icine, Houston, said he likes to treat his patients who have shallow chambers as if they are IFIS patients, too. He uses lidocaine and epineph- rine intraoperatively, as well as vis- coadaptive OVDs to tamp down the peripheral iris. Wednesday, January 18 Hot topic in glaucoma Trabecular micro-bypass stents offer a surgical solution for early to mod- erate glaucoma, according to Thomas W. Samuelson, M.D., Minneapolis, who has been heavily involved in studies of the procedure both in the U.S. and abroad. "For early to moderate disease, I'm no longer willing to subject patients to the lifelong risk of bleb-related en- dophthalmitis," said Dr. Samuelson. He added that the decision of when to operate on a patient is a complex one. "For advanced disease, I'm will- ing to give up the meshwork, go transcleral, give them the bleb with all the inherent risks, but I'm not willing to do that for early to moder- ate disease anymore," Dr. Samuelson said. "I want a procedure that will spare the meshwork and minimize so you want to have a really good view of the angle," he said. The best landmark, Dr. Samuelson added, is the scleral spur. Spotting the scleral spur will tell a surgeon where the trabecular meshwork (TM) is, since the spur is just anterior to the mesh- work. "Other landmarks are less con- sistent and harder to see."Surgeons should aim toward the top of the trabecular meshwork when implant- ing the stent at a 15-degree angle. "A very gentle touch is necessary be- cause the TM is very delicate tissue," Dr. Samuelson warned. Examining micro-bypass surgery L. Jay Katz, M.D., director of glau- coma service, Wills Eye Institute, Philadelphia, reported results from several clinical trials that examined the iStent and showed that using the stent resulted in significant lowering of medications. Patients undergoing cataract surgery and concomitant iStent implantation fared better than those who had phacoemulsification alone, according to Dr. Katz. The next wave of studies will look at using two or three stents after phacoemulsification to achieve better outflow and lower intraocular pressure, Dr. Katz said. The iStent re- ceived the CE mark in Europe in 2004 and Canadian approval in 2009. Final approval for the first-gen- eration device with the U.S. FDA is imminent, with an indication for mild to moderate open-angle glau- coma, Dr. Katz said.There are sec- ond- and third-generation iStents being investigated overseas. The sec- ond generation is a different style, but remains a trabecular meshwork stent. The third generation is a suprachoroidal device. EW MEETING REPORTER Femto-assisted phaco Surgeons continued the hot debate surrounding femto-assisted pha- coemulsification during a mini-sym- posium that touched on early astigmatic keratotomy outcomes, oc- ular docking, interface, imaging and guidance issues, as well as the top question on many surgeons' minds: Is the technology economically vi- able? "Many of us are watching for the answer to this," said John A. Vukich, M.D., surgical director, Davis Duehr Dean Center for Refrac- tive Surgery, Madison, Wis. Dr. Vukich presented a cost analysis of the technology and found that, tak- ing into account a likely click fee, if a large practice (2-3,000 cataract sur- geries per year) were to charge $1,000 per eye, it would need to per- form the surgery on an extra 18 eyes per month in year 1, 26 a month in years 2-5, and eight more a month in year 6. "The technology becomes a valuable addition to the practice in year 6," Dr. Vukich said. Currently, surgeons are only al- lowed by law to charge patients to use the laser to perform peripheral corneal relaxing incisions, which are not covered under Medicare. "The issue is very complex, but in- dustry and professional societies have initiated discussions to de- velop guidance for the physician community," said Alan E. Reider, J.D., M.P.H., attorney, Arnold & Porter LLC, Washington, D.C. Thursday, January 19 OCT blood flow analysis may be useful Optical coherence tomography (OCT) results may be an independ- ent predictor of visual field defects in glaucoma, according to one ex- pert who spoke at the 2012 Hawai- ian Eye meeting in Maui. "We're very interested in blood flow in the retina and optic nerve head because the leading causes of blindness in this country also are associated with abnormal circulation, including glaucoma, diabetic retinopathy, and macular degeneration," said David Huang, M.D., Ph.D., professor of ophthalmology and biomedical en- continued on page 100 99