Mid-term evaluation of the safety and efficacy of the iStent trabecular micro-bypass system combined with phacoemulsification.

Abstract

Micro-invasive glaucoma surgery (MIGS) and MIGS devices have been gaining increasing attention in recent years. One such device is the trabecular micro-bypass stent, or iStent® (Glaukos Corporation, Laguna Hills, USA). To evaluate the safety and efficacy of the minimally invasive ab interno surgical implantation of a trabecular bypass during cataract surgery in reducing intraocular pressure (IOP) in patients with mild and moderate open-angle glaucoma and cataracts. The study was a prospective, uncontrolled, interventional case series (a prospective study of a case series), including 54 patients with a mean age of 72 years. All subjects underwent ab interno implantation of a single iStent together with cataract surgery. The corrected distance visual acuity (CDVA), IOP, anti-glaucoma medications, visual field, and number and type of complications were investigated after surgery. The patients were followed up at 1, 7, and 30 days, and 3, 6, 12, 24 and 36 months after the operation. The mean observation time was 20 months. At baseline, CDVA was 0.5 or better in 65% of the eyes; this improved to 0.5 or better in all eyes (0.8 or better in 79%) at the end of the observation. The mean baseline IOP was 17.1 mm Hg, which fell to a mean of 15.1 mm Hg. The mean number of medicinal eye drops prescribed preoperatively was 1.7, which decreased to 0.26 at the end of the observation. Cataract surgery combined with iStent implantation seems to be an effective procedure in patients with mild to moderate open-angle glaucoma and cataracts. The insertion of 1 stent resulted in a significant decrease in IOP and a reduction in the number of topical anti-glaucoma medications needed. Based on the characteristics of the observed complications, iStent implantation can be considered a safe method.