iStent Combined with Phaco Reduces Medication Burden but Not IOP, Meta-analysis Shows

Compared to patients who underwent phaco alone, those who received iStent combined with cataract surgery were 31% more likely to be medication-free after surgery. Photo: Joseph W. Sowka, OD. Click image to enlarge. In patients with both open-angle glaucoma (OAG) and cataract, phacoemulsification alone can lower intraocular pressure, although many patients continue to require topical medications to reach and maintain their target IOP after surgery. While studies have suggested that adding an iStent may provide additional pressure reduction and lessen medication burden, the extent of its benefit beyond cataract surgery alone remains unclear. Because some studies assess patients after stopping glaucoma meds while others do not, researchers sought to determine how preoperative medication washout status influences the interpretation of surgical outcomes. Their analysis found that while iStent combined with phaco consistently reduces medication burden, its additional IOP-lowering effect is most apparent in studies that include medication washout before baseline measurements.The study, published in BMC Ophthalmology, analyzed data from five randomized controlled trials involving 915 eyes. Researchers compared outcomes of iStent or iStent inject implantation combined with phaco against phaco alone in adults with mild-to-moderate OAG and visually significant cataracts. The trials, conducted in North America, Europe and Australia, followed patients for 12 to 48 months. Researchers stratified outcomes according to whether glaucoma medications had been washed out before baseline IOP measurements and by follow-up duration.In short-term follow-up (15 months or less), the analysis found no significant difference in IOP reduction between combined surgery and cataract surgery alone, regardless of medication washout status. “This phaco-effect, driven by anterior chamber deepening and angle widening, effectively creates a physiological floor that can mask the additional hydrodynamic benefit of trabecular bypass stents in the early postoperative period,” the researchers explained in their paper.Meanwhile, long-term results told a different story: Among studies that included medication washout, combined surgery achieved significantly greater IOP reduction than phaco alone, with a weighted mean difference (WMD) of 1.29mm Hg. In studies without washout, no significant long-term IOP advantage was observed (WMD = 0.69mm Hg).While IOP findings varied by study design, medication outcomes were more consistent. Across all five trials, patients who underwent combined surgery used an average of 0.39 fewer glaucoma medications than controls. In addition, patients receiving an iStent were 31% more likely to be medication-free after surgery (relative risk: 1.31). Medication-free rates ranged from 57% to 67% in the iStent groups compared with 25% to 50% among patients undergoing cataract surgery alone.Safety outcomes were favorable in both treatment groups. Transient IOP spikes occurred in nine eyes in the iStent group and four eyes in controls, while secondary filtration surgery was required in seven and four eyes, respectively. Based on these findings, the study authors argue that medication washout status should be considered when interpreting glaucoma surgery trials, as its role “represents a critical methodological factor underlying the variability of reported IOP outcomes across trials in the long term.” They concluded that in patients whose IOP is already well controlled on topical therapy, additional numerical IOP reduction following iStent implantation may be limited; however, the procedure may offer meaningful benefits through reduced medication burden, potentially improving adherence and minimizing ocular surface disease associated with chronic drop use.Click here for the journal source. Song Z, Li Y, Wang Y, et al. iStent combined with phacoemulsification versus phacoemulsification alone in open-angle glaucoma: a meta-analysis by medication washout status. BMC Ophthalmol. June 8, 2026. [Epub ahead of print] This article was developed by the editorial staff in conjunction with experts in the field. In the process, AI may have been among the editorial tools used to meet the goals of human editors, who approved all content.