Prospective, Randomized, Controlled Pivotal Trial of an Ab Interno Implanted Trabecular Micro-Bypass in Primary Open-Angle Glaucoma and Cataract
Authors: Thomas W. Samuelson, Steven R. Sarkisian, David M. Lubeck, Michael C. Stiles, Yi-Jing Duh, Eeke A. Romo, Jane Ellen Giamporcaro, Dana M. Hornbeak, L. Jay Katz, William Bartlett, Carlos Buznego, Starck Johnson, Francis A. D'Ambrosio, Doug Dehning, Harvey DuBiner, Raj Goyal, Bret Hughes, Robert E. Marquis, Robert Noecker, Shachar Tauber, Bernard R. Perez, Lawrence Roel, Steven Sarkisian, Steven Silverstein, Steven Day, Kerry Solomon, Farrell Tyson, Steven Vold, Thomas Samuelson, Steven Simmons, Michael Stiles, Quang H. Nguyen, Kent P. Bashford, Brian Flowers, William J. Flynn, Joseph Gira, Constance Okeke, George R. Reiss, Sydney L. Tyson, Greg Parkhurst, John Linn, David Lubeck, Jonathan Solomon, Inder Paul Singh, R. Duncan Johnson, Christopher Lin, Joshua W. Kim, Charles J. Crane, Frank Cotter
Journal: Ophthalmology (2019)

PurposeEvaluate the safety and effectiveness of an ab interno implanted (iStent inject) Trabecular Micro-Bypass System (Glaukos Corporation, San Clemente, CA) in combination with cataract surgery in subjects with mild to moderate primary open-angle glaucoma (POAG).DesignProspective, randomized, single-masked, concurrently controlled, multicenter clinical trial.ParticipantsEyes with mild to moderate POAG and preoperative intraocular pressure (IOP) ≤24 mmHg on 1 to 3 medications, unmedicated diurnal IOP (DIOP) 21 to 36 mmHg, and cataract requiring surgery.MethodsAfter uncomplicated cataract surgery, eyes were randomized 3:1 intraoperatively to ab interno implantation of iStent inject (Model G2-M-IS; treatment group, n = 387) or no stent implantation (control group, n = 118). Subjects were followed through 2 years postoperatively. Annual washout of ocular hypotensive medication was performed.Main Outcome MeasuresEffectiveness end points were ≥20% reduction from baseline in month 24 unmedicated DIOP and change in unmedicated month 24 DIOP from baseline. Safety measures included best spectacle-corrected visual acuity (BSCVA), slit-lamp and fundus examinations, gonioscopy, pachymetry, specular microscopy, visual fields, complications, and adverse events.ResultsThe groups were well balanced preoperatively, including medicated IOP (17.5 mmHg in both groups) and unmedicated DIOP (24.8±3.3 mmHg vs. 24.5±3.1 mmHg in the treatment and control groups, respectively, P = 0.33). At 24 months, 75.8% of treatment eyes versus 61.9% of control eyes experienced ≥20% reduction from baseline in unmedicated DIOP (P = 0.005), and mean reduction in unmedicated DIOP from baseline was greater in treatment eyes (7.0±4.0 mmHg) than in control eyes (5.4±3.7 mmHg; P < 0.001). Of the responders, 84% of treatment eyes and 67% of control eyes were not receiving ocular hypotensive medication at 23 months. Furthermore, 63.2% of treatment eyes versus 50.0% of control eyes had month 24 medication-free DIOP ≤18 mmHg (difference 13.2%; 95% confidence interval, 2.9–23.4). The overall safety profile of the treatment group was favorable and similar to that in the control group throughout the 2-year follow-up.ConclusionsClinically and statistically greater reductions in IOP without medication were achieved after iStent inject implantation with cataract surgery versus cataract surgery alone, with excellent safety through 2 years.