IStent Inject Device Lowers IOP After Cataract Surgery in Glaucoma Patients

Medscape
18 Apr, 2019 ,

In patients with mild to moderate glaucoma and cataract, the second-generation iStent inject system, with two redesigned stents, reduces intraocular pressure (IOP) more than cataract surgery alone, according to results of a new pivotal trial. The most important finding is that the iStent inject, when done with cataract surgery, can improve the likelihood that unmedicated IOP is reduced by 20% or more compared to cataract surgery alone.

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In patients with mild to moderate glaucoma and cataract, the second-generation iStent inject system, with two redesigned stents, reduces intraocular pressure (IOP) more than cataract surgery alone, according to results of a new pivotal trial.

"The most important finding is that the iStent inject, when done with cataract surgery, can improve the likelihood that unmedicated IOP is reduced by 20% or more compared to cataract surgery alone," Dr. Pradeep Ramulu, a professor of ophthalmology at Johns Hopkins Wilmer Eye Institute in Baltimore, Maryland, told Reuters Health by email.

"Here, two stents were inserted (instead of one with the first-generation device), and the device was re-engineered for easier use and insertion. It was important to know that the new device added value," said Dr. Ramulu, who was not involved in the study.

In the multicenter trial, researchers randomly assigned 118 eyes to no stent and 387 eyes to implantation with the iStent inject Trabecular Micro-Bypass System (Model G2-M-IS from Glaukos Corporation). All eyes had mild to moderate primary open-angle glaucoma (POAG) and preoperative IOP of 24 mmHg or lower on one to three medications, unmedicated diurnal IOP (DIOP) of 21 to 36 mmHg and cataract requiring surgery.

Participants were followed for two years after surgery, and washout of ocular hypotensive medication was performed at months 11 and 23 to enable tests for unmedicated DIOP at months 12 and 24.

At 24 months, 75.8% of treated eyes, compared with 61.9% of control eyes, dropped 20% or more from baseline in unmedicated DIOP (P=0.005), report Dr. Thomas W. Samuelson of Minnesota Eye Consultants in Minneapolis and colleagues in Ophthalmology, online March 14.

The mean drop from baseline in unmedicated DIOP was greater in the treated eyes than in the control eyes (7.0 vs. 5.4 mmHg; P<0.001). Among the responders, 84% of treated eyes and 67% of control eyes were not being given ocular hypotensive medication at 23 months.

Overall, 63.2% of stented eyes compared with 50.0% of control eyes had 24-month medication-free DIOP of 18 mmHg or less.