EyeWorld Asia-Pacific June 2011 Issue

June 2011 15 EW FEATURE continued on page 17 Placement of the Ex-PRESS Glaucoma Filtration Device Source: Alcon For patients with both cataract and glaucoma, new drainage devices may provide a more definitive solution W hen patients develop a cataract and glaucoma, often a surgeon’s first line of defense is to combine phacoemulsification and trabeculectomy to extract the cataract and achieve adequate IOP control. “If the patient has early glaucoma and a cataract, phaco combined with endoscopic cyclophotocoagulation or phaco combined with Trabectome [NeoMedix, Tustin, Calif., USA] may be good options,” said Steven R. Sarkisian Jr., MD, director of the glaucoma fellowship, Dean A. McGee Eye Institute, and clinical associate professor of ophthalmology, University of Oklahoma, Oklahoma City, Okla., USA. “If the patient wants something more definitive, phaco combined with canaloplasty or the Ex-PRESS Glaucoma Filtration Device [Alcon, Fort Worth, Texas, USA/Hünenberg, Switzerland] may be better, the latter 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., USA) and the Baerveldt Glaucoma Implant (Abbott Medical Optics, AMO, Santa Ana, Calif., USA). 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. They can be performed alone or in a combined phaco procedure. Iqbal (Ike) K. Ahmed, MD, assistant professor, University of Toronto, Canada, and clinical Glaucoma drainage devices have increasing role in advanced disease by Jena Passut EyeWorld Staff Writer 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 assistant professor, University of Utah, Salt Lake City, Utah, USA, said the devices have long been a second-line or third-line option, but “there’s a trend now for surgeons to go to these devices earlier.” Patients with neovascular glaucoma, extensive diabetic retinopathy, 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, MD, attending surgeon, Minnesota Eye Consultants, Minneapolis, Minn., USA, and adjunct associate professor, University of Minnesota, Minneapolis, Minn., USA, 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 disease 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’ approach reduces risk and takes no option off the table,” Dr. Samuelson said. “Importantly, it is the option that I would want if I were the patient, at least at this point in time.” If the disease is more advanced or the patient has failed previous incisional glaucoma surgery, Dr. Samuelson will move on to a combined procedure—either phaco with trabeculectomy or with an aqueous drainage device such as the Baerveldt implant. “Combined surgery in this setting is a terrific opportunity to improve visual function and stabilize IOP,” Dr. Samuelson said. “I am very enthusiastic about the intense interest in minimally invasive glaucoma surgery techniques currently in trials such as the iStent Trabecular Micro-Bypass [Glaukos, Laguna Hills, Calif., USA], as well as available techniques such as Trabectome. As less invasive and safer procedures become available, the opportunity to combine surgical procedures will expand to those with less advanced disease.” Surgeons are using the drainage devices more for advanced glaucoma, citing their long-term efficacy and reduced risk of infection. Dr. Ahmed’s colleague, Nir Shoham, MD, presented a paper at the ASCRS•ASOA Symposium & Congress in San Diego comparing cataract extraction with the two drainage devices. “This retrospective, single surgeon study of 66 eyes compared outcomes of combined phacoemulsification with either Ahmed Glaucoma Valve (N=41) or Baerveldt Glaucoma Device (N=25),” according to the abstract. “Surgical success was defined as reduction in intraocular pressure (IOP) >20%, an absolute 5 mmHg ≤ IOP ≤ 18 mm Hg, with or without glaucoma medications, no loss of light perception, no vision threatening complications and without further glaucoma surgery.” The mean IOP and glaucoma medications after 1 year were comparable between the two groups, although the phaco/ Baerveldt group had a significantly higher IOP than the phaco/Ahmed group at 1 day (P<0.001) and 1 week (P<0.001) and a higher use of glaucoma medication classes