NOV 2012

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

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42 EW FEATURE February 2011 Cataract/glaucoma combined surgeries November 2012 Considering a combined cataract and aqueous shunt procedure for glaucoma patients by Vanessa Caceres EyeWorld Contributing Writer These photos show an uncomplicated cataract-tube procedure and one that is complicated by post-op fibrin formation. The fibrin compromises the visual outcome Source: Herbert Fechter, M.D. AT A GLANCE • Combined cataract and aqueous shunt surgery, can be a good ap- proach in a select group of patients • This procedure is used by some surgeons when trabeculectomy is unlikely to be successful, such as patients with uveitic and neovascular glaucoma • Not all surgeons favor this proce- dure; although drainage devices are used more often in surgery nowa- days, there's also a trend to moving away from combined procedures M any glaucoma surgeons agree that a combined cataract and aqueous shunt proce- dure works in the right glaucoma patient. However, they add that this particular ap- proach is not called for very often. "In these patients, it's like you instantly give them the bionic eye," said Douglas J. Rhee, M.D., associ- ate professor, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston. Dr. Rhee believes surgeons should be encouraged to perform more cataract/aqueous shunt procedures in the right pa- tients. That said, he also thinks the approach doesn't get enough public- Glaucoma continued from page 40 "For now, we know the iStent offers a safe option for patients undergoing cataract surgery," Dr. Craven said. EW Editors' note: Dr. Vold has financial interests with Glaukos, Transcend Medical, AqueSys (Irvine, Calif.), Ivantis, NeoMedix (Tustin, Calif.), iScience Interventional (Menlo Park, Calif.), and SOLX (Waltham, Mass.). Dr. Lewis has financial interests with AqueSys, Glaukos, and Ivantis. Dr. Craven has financial interests with Glaukos, Transcend Medical, and Ivantis. Dr. Bacharach has financial interests with Glaukos. Contact information Bacharach: jb@northbayeye.com Craven: ercraven@yahoo.com Lewis: rlewiseyemd@yahoo.com Vold: svold@cox.net ity. "You don't classically think of them together," he said. This may be because such a small number of patients are well qualified for the procedure, he added. To be clear—as the physicians interviewed for this article noted that terminology can get tricky— this approach focuses on cataract surgery combined with aqueous shunts (also known as tube shunts, glaucoma drainage implants, and setons)—the use of a Molteno implant (Molteno Ophthalmic Ltd., Dunedin, New Zealand), Baerveldt Glaucoma Implant (Abbott Medical Optics, AMO, Santa Ana, Calif.), or Ahmed Glaucoma Valve (New World Medical, Rancho Cucamonga, Calif.). Although these implants are often grouped together with the EX-PRESS device (Alcon, Fort Worth, Texas), the EX-PRESS is more of an adjunct to a trabeculectomy, said Steven J. Gedde, M.D., professor of ophthalmology, Bascom Palmer Eye Institute, Miami. Additionally, placement of an EX-PRESS versus an aqueous shunt is different, Dr. Rhee added. The ideal patient Keeping that in mind, patients who are best suited for a combined cataract/aqueous shunt approach usu- ally meet some uncommon criteria. "The patient might have high pressure in the context of a complex case in which you think it is likely that a trabeculectomy will fail," said Adam Reynolds, M.D., Boise, Idaho. "It might be a complex uveitic case or a complex pediatric case with trauma, or maybe neovas- cular glaucoma where you know a trabeculectomy likely will not work." Although Dr. Reynolds rarely performs this particular combined procedure, he gave an example of a patient he was planning to treat with the approach—a 13-year-old female with Down's syndrome who had idiopathic chronic uveitis, a severe posterior subcapsular cataract, and out-of-control IOP. Dr. Rhee will use this surgical approach in patients with moderate to advanced disease who are monoc- ular. Because of the risk of double vision with the combined approach, he will also consider patients where the difference between the two eyes is so great that double vision, if it occurs, is not problematic. He performs a combined cataract and aqueous shunt procedure about once a month. Patients with a failed trabeculec- tomy—or at high risk for trabeculec- tomy failure—are another group to consider, said Dr. Gedde. "I've used these devices in patients where I think the likelihood of a trabeculec- tomy working is lower," he said. "This may include eyes with prior ocular surgery and associated con- junctival scarring, such as a failed trabeculectomy, vitrectomy, or scleral buckling procedure. There are also types of secondary glaucoma where shunts are better procedures, like neovascular and uvetic glau- coma. If there is a visually signifi- cant cataract present, you can consider removing the cataract at the same time." In fact, there are some geo- graphical areas in which the failure rate for trabeculectomy is so high due to the patient population, it is more common to go right to use of an aqueous shunt—and combine with cataract surgery if necessary, Dr. Reynolds said. That all said, LTC (Ret.) Herbert P. Fechter, M.D., Augusta, Ga., rarely finds patients suited for this approach. "If the intraocular pres- sure is too high, I go straight to the tube. If the pressure is borderline, I'll attempt to achieve pressure control with just the cataract surgery alone. Patients with neovascular glaucoma or uveitic glaucoma do better when their glaucoma and inflammation is controlled prior to cataract surgery," he said. Post-op inflammation can lead to anterior chamber fibrin for- mation and possible cystoid macular edema, affecting chances for quick visual rehabilitation, Dr. Fechter added. Performing cataract surgery alone may help control pressure in patients with early glaucoma or angle-closure glaucoma, Dr. Fechter said. In patients with marked pres- sure elevation in the 50s or 60s and a cataract, Dr. Gedde prefers to perform the least amount of surgery necessary, focusing first on control- ling the intraocular pressure with glaucoma surgery. Considering the advantages, drawbacks Once you decide a patient would benefit from a combined cataract/ aqueous shunt procedure, what pros and cons can be expected? First, shunts have been shown to accelerate cataract growth, Dr. Rhee said. However, if you are using a combined procedure like this one, that isn't a concern. Second, there is a well-defined rate (about 5%) of double vision, he continued on page 44

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