Six-Month Outcomes from a Prospective, Randomized Study of iStent infinite Versus Hydrus in Open-Angle Glaucoma: The INTEGRITY Study.

introductionThis was a prospective, randomized, double-masked, multicenter, 24-month study to compare effectiveness and safety outcomes following standalone implantation of two types of current generation trabecular stents in adults with open-angle glaucoma (OAG). An interim analysis was performed at month 6.

methodsEyes with OAG, mean IOP ≤ 24 mmHg on zero to three intraocular pressure (IOP)-lowering medications at screening, and with baseline mean diurnal IOP (MDIOP) 21-36 mmHg after medication washout were randomized to standalone implantation of the current generation of three trabecular micro-bypass stents (iStent infinite) or one trabecular bypass stent (Hydrus). Eyes on medication were to undergo a medication washout prior to the month 6 visit. Analyses included a comparison of the proportion of iStent infinite versus Hydrus eyes achieving MDIOP reduction of 20% or greater from baseline at month 6. Reduction from baseline in MDIOP and number of medications were also assessed. Safety parameters included intraoperative/postoperative complications, corrected visual acuity, slit-lamp biomicroscopy, ophthalmoscopy, gonioscopy, perimetry, and adverse events.

resultsEyes with primarily mild-to-moderate disease severity were randomized: 91 iStent infinite eyes had screening mean (± standard deviation [SD]) IOP of 17.0 ± 3.2 mmHg on 1.6 ± 0.9 medications and baseline unmedicated MDIOP of 23.7 ± 2.9 mmHg; 89 Hydrus eyes had screening mean (± SD) IOP of 17.1 ± 3.3 mmHg on 1.5 ± 0.9 medications and baseline unmedicated MDIOP of 23.5 ± 2.7 mmHg. At month 6, a similar proportion of iStent infinite eyes (82.7%) versus Hydrus eyes (78.9%) achieved MDIOP reduction ≥ 20% from baseline regardless of IOP medication use or surgical complications. The difference was statistically significantly different (78.2% iStent infinite versus 65.0% Hydrus) for unmedicated MDIOP reduction ≥ 20% from baseline in eyes with no surgical complications (difference 13.2%; 95% confidence interval (CI) 3.0%, 23.3%). Mean MDIOP change from baseline, regardless of IOP medication use or surgical complications, was similar between groups (- 7.4 ± 2.9 mmHg iStent infinite and - 7.2 ± 2.9 mmHg Hydrus), whereas unmedicated MDIOP change from baseline without surgical complications was statistically significantly superior in iStent infinite eyes (- 6.8 ± 4.1 mmHg) versus Hydrus eyes (- 5.7 ± 4.1 mmHg) (difference - 1.1 mmHg; 95% CI - 2.0 mmHg, - 0.2 mmHg). Improper stent placement was reported in one iStent infinite and seven Hydrus eyes (1.1% versus 7.9%). One iStent infinite versus four Hydrus eyes experienced peripheral anterior synechiae > 1 mm (1.1% versus 4.5%). Overall, there were significantly fewer surgical complications in the iStent infinite eyes (3.3%) compared to Hydrus eyes (16.9%; difference of - 13.6%, 95% CI - 23.8%, - 3.4%).

conclusionsIn this study of standalone implantation of current trabecular stent technologies in subjects with OAG, high proportions in both groups achieved clinically meaningful IOP reduction. When considering surgical complications as failures, a statistically significantly greater proportion of iStent infinite eyes versus Hydrus eyes had no surgical complications and achieved an unmedicated MDIOP reduction of ≥ 20%. The iStent infinite group also had clinically relevant and statistically significantly superior reduction from baseline in unmedicated MDIOP without surgical complications compared to Hydrus.

trial registrationClinicalTrials.gov identifier, NCT05127551.