Eyeworld

EW FEATURE 54 Glaucoma and the cataract patient • February 2017 AT A GLANCE • The ideal MIGS patient generally has mild to moderate glaucoma and requires a modest drop in IOP. • Factors that surgeons consider before MIGS procedures in a patient include age, glaucoma severity, lifestyle and quality of life, cost, and type of glaucoma. • Surgeons use standalone MIGS, MIGS with cataract extraction, and combined MIGS procedures to help patients reach target IOP goals. • Comfort with intraoperative gonioscopy is crucial for the performance of MIGS. by Vanessa Caceres EyeWorld Contributing Writer considerations also factor into treatment decisions. • Type of glaucoma. If perform- ing MIGS as an outflow proce- dure such as with the iStent or Trabectome (NeoMedix, Tustin, California), primary or secondary open-angle glaucoma is ideal, Dr. Francis said. In contrast, patients with neovascular glaucoma are contraindicated for MIGS, he said. The MIGS approach is not suited for patients with a poor angle view, low-tension glaucoma, or patients with extremely advanced glaucoma who need very low IOP. in combination with phacoemulsi- fication would be the go-to choices if a patient has a cataract, as the procedure would be covered by insurance, Dr. Shareef said. • Quality of life and lifestyle factors. In glaucoma patients with a slow progressive rate of vi- sual field loss who could go blind by their eighth or ninth decade, Dr. Shareef prefers combined MIGS, especially if they live alone, travel a long distance, are unable to come for postop visits, are highly functional, or are mon- ocular. Patient career and hobby a modest drop—20% to 30%—in IOP to stabilize their glaucoma," said Shakeel Shareef, MD, associate professor, Flaum Eye Institute, Uni- versity of Rochester, Rochester, New York. Other surgeons interviewed by EyeWorld generally echoed Dr. Shareef's description. "It's best if the IOP is a little elevated—say, 20 to 25—because the patients with the highest preoper- ative IOP have the biggest drop in IOP postop," said Reay Brown, MD, Atlanta Ophthalmology Associates, Atlanta. "The goal in all cases is to lower IOP and eliminate one or two of the drops." Dr. Brown has occa- sionally used MIGS in patients on three medications with pressure in the low 30s; however, these patients have also had good visual fields. Eight factors to review before surgery Here are specific factors that sur- geons consider with potential MIGS patients: • Glaucoma severity. Patients need- ing MIGS usually—although not always—have mild to moderate glaucoma. • Age. "If a patient is elderly and needs a modest drop in IOP, I would opt for a MIGS procedure over a more invasive interven- tion such as filtration surgery or a shunt device. The goal is not to make the cure worse than the disease," Dr. Shareef said. • Balancing IOP reduction and medication use. "I have tradition- ally reserved the iStent [Glaukos, San Clemente, California] for pa- tients who required reduction of glaucoma medications while not requiring great reduction in their baseline IOP," said Malik Kahook, MD, Slater Family Endowed Chair in Ophthalmology, and chief of the glaucoma service, University of Colorado, Aurora, Colorado. In contrast, when a patient needs a reduction in both IOP and medi- cation use, he is more likely to use ab interno goniotomy procedures. • Anatomy. In patients with an immobile conjunctiva in which ab externo surgery is not an option, MIGS is the procedure of choice, Dr. Shareef said. • Cost. The Food and Drug Adminis- tration-approved MIGS procedures Surgeons must weigh various factors when considering the use of standalone versus combined procedures W hen selecting patients for microinvasive glaucoma surgery (MIGS), there are certain factors that make for ideal patients. However, there's also some "art of medicine" involved as physicians consider patients' lifestyle issues. For instance, there may be the yoga instructor who does inverted poses and wants to avoid a tra- beculectomy, or the open-water swimmer who doesn't want tube shunts, or the older patient who has problems using eye drops. "It's not just about target IOP," said Brian Francis, MD, professor of oph- thalmology, Doheny Eye Institute, University of California, Los Ange- les. "You have to get into patient limitations, lifestyles, and what they like to do. You have to get a feel for if they'll be contraindicated for standard filtering surgery." Still, an ideal MIGS patient usually has several characteristics. It's a "patient with mild to moderate open-angle glaucoma controlled on one or two glaucoma medica- tions with stable visual field loss who wishes to reduce the burden of taking medications or is intolerant to glaucoma medications and needs Selecting the ideal patient for MIGS Proper anatomic insertion of two iStents within Schlemm's canal 1 clock hour apart with patent snorkel Source: Rachel Hollar, CRA continued on page 56 iStent is well placed within Schlemm's canal in an area with moderate trabecular meshwork pigmentation. Source: Brittany Richardson, CRA

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