Eyeworld

EW FEATURE 96 by Jena Passut EyeWorld Staff Writer Glaucoma drainage devices have increasing role in advanced disease W hen patients develop a cataract and glau- coma, often surgeons' first line of defense is to combine pha- coemulsification and trabeculec- tomy to extract the cataract and achieve adequate IOP control. "If the patient has early glaucoma and a cataract, phaco combined with endoscopic cy- clophotocoagulation or phaco com- bined with Trabectome (NeoMedix, Tustin, Calif.) may be good options," said Steven R. Sarkisian Jr., M.D., director of the glaucoma fellowship, Dean A. McGee Eye Institute, and clinical associate professor of oph- thalmology, University of Okla- homa, Oklahoma City. "If the patient wants something more de- finitive, phaco combined with canaloplasty or the EX-PRESS Glau- coma Filtration Device (Alcon, Fort Worth, Texas) may be better, the lat- ter option being especially useful if you really need to keep the patient off all medications." For patients who have more advanced forms of glaucoma or who have had previous surgery failures, surgeons may opt to implant an aqueous drainage device. Two such devices are the Ahmed Glaucoma Valve (New World Medical, Rancho Cucamonga, Calif.) and the Baerveldt Glaucoma Implant (Abbott Medical Optics, AMO, Santa Ana, Calif.). These procedures introduce a tube into the eye that carries aque- ous humor from the inside of the eye to a reservoir implanted under the conjunctiva. They can be per- formed alone or in a combined phaco procedure. Iqbal (Ike) K. Ahmed, M.D., assistant professor, University of Toronto, and clinical assistant pro- fessor, University of Utah, Salt Lake City, said the devices have long been a second-line or third-line option, but "there's a trend now for sur- geons to go to these devices earlier." Patients with neovascular glau- coma, extensive diabetic retinopa- thy, or aggressive uveitis are good candidates for the combined phaco- drainage device procedure. "They tend to scar more," Dr. Ahmed said, adding that patients with a poor conjunctiva or who have failed initial surgery would benefit as well. For his part, Thomas W. Samuelson, M.D., attending sur- geon, Minnesota Eye Consultants, Minneapolis, and adjunct associate professor, University of Minnesota, reported doing fewer combined glaucoma procedures than he has in the past. "The accumulating data that phacoemulsification lowers IOP has led me to utilize cataract surgery as an incremental step in glaucoma management, especially if the dis- ease is mild and the patient has disc and visual field reserve," he said. Simply removing the cataract often adequately lowers IOP if the glaucoma is mild or moderate. Dr. Samuelson said he can then reassess and move on to more aggressive glaucoma management if needed. "I believe this 'minimalist' ap- proach reduces risk and takes no op- tion off the table," Dr. Samuelson said. "Importantly, it is the option that I would want if I were the pa- tient, at least at this point in time." If the disease is more advanced or the patient has failed previous in- cisional glaucoma surgery, Dr. Samuelson will move on to a com- bined procedure—either phaco with trabeculectomy or with an aqueous drainage device such as the Baerveldt implant. "Combined surgery in this set- ting is a terrific opportunity to im- prove visual function and stabilize IOP," Dr. Samuelson said. "I am very enthusiastic about the intense inter- est in minimally invasive glaucoma surgery techniques currently in trials such as the iStent Trabecular Micro- Bypass (Glaukos, Laguna Hills, Calif.), as well as available tech- niques such as Trabectome. As less invasive and safer procedures be- come available, the opportunity to combine surgical procedures will ex- pand to those with less advanced disease." Surgeons are using the drainage devices more for advanced glau- coma, citing their long-term efficacy and reduced risk of infection. A Baerveldt drainage device and Ahmed drainage device implanted inferiorly, at varying degrees of magnification Source: Leon W. Herndon, M.D. AT A GLANCE • For patients who have advanced forms of glaucoma or who have had previous surgery failures, surgeons may consider aqueous drainage devices • Patients with a less-than-perfect conjunctiva are indicated for shunt procedures because the shunt can be implanted into the pars plana • These procedures introduce a tube into the eye that carries aqueous humor from the inside of the eye to a reservoir implanted under the conjunctiva • The intermediate-term results of the multicenter, randomized, clinical TVT study support the use of tube shunts, even beyond refractory glaucoma February 2011 COMBINED SURGERY March 2011

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