Influence of High Myopia on Outcomes of iStent Inject W Implantation Combined with Cataract Surgery up to 24 Months of Follow-Up

<b>Background</b>: The purpose of this study was to evaluate the 2-year postoperative outcomes of iStent inject W implantation combined with phacoemulsification, with a specific focus on comparing results between high myopia (HM) and non-high myopia (non-HM) eyes. <b>Methods</b>: In this retrospective study, subjects were divided into HM and non-HM groups using an axial length cut-off of 26.0 mm. The main outcome measures were intraocular pressure (IOP), number of glaucoma medications, surgical success rates, and postoperative complications. Surgical success was defined as a decrease in glaucoma medical therapy of ≥1 medication without an increase in IOP, or a postoperative IOP ≤ 21 mmHg with a ≥20% reduction. Changes from baseline were analyzed up to 24 months postoperatively. <b>Results</b>: The non-HM group achieved a significant IOP reduction at all postoperative time points. The HM group showed no significant postoperative IOP reduction except at 3 months. The mean number of medications significantly decreased from baseline to 24 months in two groups. The cumulative surgical success rate at 24 months was 48.6% in the non-HM group, whereas it was significantly lower at 19.4% in the HM group (<i>p</i> = 0.038). No significant difference in the incidence of postoperative complications was observed between the groups. <b>Conclusions</b>: The IOP-lowering efficacy of iStent inject W implantation combined with phacoemulsification appeared limited in eyes with HM. These results may suggest the need for careful patient selection and clinical judgment when considering iStent inject W implantation in this population.