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63 EW GLAUCOMA August 2015 Randomized evaluation of the trabecular micro-bypass stent with phacoemulsifica- tion in patients with glaucoma and cataract. Ophthalmology. 2011;118:459–467. of the group receiving 1 stent, 90% of those receiving 2, and 92% of those receiving 3 had IOP reduction ≥20% without medication. Fifty-sev- en percent, 78%, and 84% of 1-, 2-, and 3-stent eyes, respectively, had month 12 IOP reduction ≥40% with- out medication. All eyes had month 12 IOP ≤18 mm Hg regardless of medica- tion, and approximately 90% had month 12 IOP ≤18 mm Hg without medication in all groups. The 3 respective groups had month 12 IOP ≤15 mm Hg without medication in 65%, 85%, and 92%. A few subjects required a postoperative medication due to elevated IOP at visits ranging from month 1 through month 18. Overall, results through 18 months show significant IOP reduction after implantation with a single stent, with further IOP reduction after implantation with multiple stents. There was an overall favorable safety profile in patients, with no intraoperative sequelae and a very low rate of postoperative sequelae. When performed as a stand- alone procedure, the iStent is insert- ed through a 1.5 mm corneal inci- sion and placed in Schlemm's canal through the lower nasal quadrant. When inserting multiple stents, I try to place them as far apart as possible while still maintaining a reason- able view through the gonioscope. Adding more stents creates incre- mental and titratable control of IOP. Physicians can use their discretion when deciding how many stents are necessary by factoring in the pa- tient's IOP, the severity of the visual field loss, nerve damage, family his- tory, and other determining issues. In general, for patients with early or mild glaucoma with a goal of an IOP of 18 mm Hg, 1 stent is likely suffi- cient. The more severe the disease or the lower the IOP goal, the more stents can be added. In this study, all patients did well and only progression of pre- existing cataracts in a few phakic pa- tients was observed. One limitation of the study is that the crystalline lens was not quantitatively assessed before and after stent placement. In the future, the crystalline status should be assessed ahead of time. EW References 1. Friedman D, O'Colmain B, eds. Prevent Blindness America. Vision Problems in the U.S.: Glaucoma. www.visionproblemsus.org/ glaucoma.html. Published 2012. Accessed January 20, 2014. 2. Okeke CO, Quigley HA, Jampel HD, et al. Adherence with topical glaucoma medication monitored electronically the Travatan Dosing Aid study. Ophthalmology 2009;116:191–9. 3. Samuelson TW, Katz LJ, Wells JM, Duh YJ, Giamporcaro JE; US iStent Study Group. continued on page 64

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