iStent Inject (Second-generation Trabecular Microbypass) Versus Nonpenetrating Deep Sclerectomy in Association With Phacoemulsification for the Surgical Treatment of Open-angle Glaucoma and Cataracts: 1-Year Results

Precis: Both nonpenetrating deep sclerectomy (NPDS) and iStentinjectare safe and effective when combined with phacoemulsification. The NPDS group presented lower final intraocular pressure (IOP); however, more postoperative intervention and longer recovery time was required. Aim: The aim of this study was to assess the 1-year efficacy and safety of second-generation trabecular microbypass stent implantation (iStent inject) versus NPDS in association with phacoemulsification (Phaco) for the concomitant surgical treatment of open-angle glaucoma and cataracts. Materials and Methods: This was a single-center longitudinal retrospective comparative study of eyes treated with Phaco-NPDS, with adjunctive use of collagen matrix implant and mitomycin C (group 1), or Phaco-iStent inject (group 2). The main outcome measures were success rates [absolute success: proportion of eyes with IOP<18 mm Hg without any glaucoma medication; relative success: proportion of eyes achieving different target IOPs (<18; <15; and <12 mm Hg) with or without medication]; mean reduction (%) in IOP and medication use; number of postoperative reinterventions (goniopuncture, needling, and reoperation); and number of complications. Results: The mean age (y) was 69.3 in group 1 and 72.7 in group 2. Groups 1 (n=51) and 2 (n=32) achieved absolute success rates of 74.5% and 81.3%, respectively (P=0.333). Concerning relative success rates, no significant difference was found for IOP<18 mm Hg or an IOP<15 mm Hg between the 2 groups. However, significantly more eyes achieved an IOP <12 mm Hg in the Phaco-NPDS group. The mean percentage of IOP reduction from baseline to the end of follow-up was also statistically higher in group 1 (39.9% vs. 24.5%). Both groups achieved similar results in the mean reduction of medications per eye. No significant complications were found in either group, but patients in group 1 required more postoperative intervention than group 2. Conclusions: Both techniques are safe and effective for the concomitant surgical treatment of open-angle glaucoma and cataracts and presented comparable relative success rates at different target IOP levels (<18 and <15 mm Hg). A larger proportion of patients in group 1 achieved a target IOP <12 mm Hg; however, more postoperative intervention was required.