iStent with cataract surgery produces long-term IOP reduction

This study assessed the safety and efficacy of ab interno implantation of iStent inject in combination with cataract surgery in patients with primary open-angle glaucoma (POAG).

Study design

This multicenter, prospective, randomized clinical trial included 505 eyes randomized to receive cataract surgery with (n=387) or without (n=118) iStent implantation. Patients were followed for 2 years postoperatively. The primary endpoint was a 20% or more reduction in diurnal IOP (DIOP) without medication use at 2 years. The secondary endpoint was the average reduction in unmedicated DIOP.

Outcomes

Approximately 76% of the iStent and 62% of the control group met the primary efficacy endpoint (P=0.005). The average unmedicated drop in DIOP was greater in patients receiving iStent than in controls (7 mm Hg vs 5.4 mm Hg; P<0.001). Of the responders, 84% of treatment and 67% of control eyes were medication-free by 23 months. At 24 months, 63% of treatment eyes and 50% of control eyes achieved DIOP less than 18 mm Hg without medication. There were no unanticipated adverse events.

Limitations

The main limitation of the study was the inability to mask surgeons to the treatment groups. The data set included the surgeons’ learning curve with the procedure.

Clinical significance

All eyes, regardless of medication use, achieved a reduction of IOP, but the mean reduction was greatest in patients who underwent combined iStent inject and cataract procedures. Medication use also declined with the iStent, although it was not a study endpoint. The study demonstrated the safety and efficacy of the iStent inject in reducing IOP and medication use for patients with cataract and mild to moderate glaucoma.