Multicenter Effectiveness and Disease Stability Through 3 Years After iStentTrabecular Micro-Bypass with Phacoemulsification in Glaucoma and Ocular Hypertension

Abstract

Purpose: To evaluate 3-year safety and efficacy of two second-generation trabecular micro-bypass stents. (iStent inject®) with phacoemulsification. Materials and Methods: This multicenter retrospective study of iStent inject implantation with phacoemulsification included data from eight surgeons across Australia. Eyes with cataract and mild to advanced glaucoma [predominantly primary open-angle (POAG), primary angle closure (PAC), or normal-tension (NTG) glaucoma] or ocular hypertension (OHT) were included. Study assessments included intraocular pressure (IOP); number of ocular hypotensive medications; proportions of eyes with 0, 1, 2, or ≥3 IOP-lowering medications; IOP ≤15 mmHg or ≤18 mmHg; visual fields (VF); retinal nerve fiber layer thickness (RNFL); central corneal thickness (CCT); intraoperative complications; adverse events; and secondary surgeries. Results: A total of 273 eyes underwent surgery and had 36-month follow-up. At 36 months versus preoperative, mean IOP decreased by 15.5% (16.4±4.6 mmHg to 13.9±3.5 mmHg; p<0.001), and 70.3% of eyes achieved IOP of ≤15 mmHg (versus 49.1% preoperatively; p<0.001). The mean medication burden decreased by 68.5% (from 1.51±1.17 to 0.48±0.89 medications; p<0.001); 71.4% of eyes were medication-free (versus 21.6% preoperatively; p<0.001), while 6.2% of eyes were on ≥3 medications (versus 22.3% preoperatively; p<0.001); 96.3% of eyes maintained or reduced medications vs preoperative. Significant IOP and medication reductions occurred across glaucoma subtypes (POAG, PAC, NTG, OHT): 13–22% for IOP (p<0.05 for all) and 42–94% for medication (p<0.05 for all). Favorable safety included few adverse events; stable VF, RNFL, and CCT; and filtering surgery in only 8 eyes (2.9%) over 3 years. Conclusion: In this multicenter cohort from 8 surgeons across Australia, significant IOP and medication reductions were sustained through 3 years after iStent inject implantation with phacoemulsification. Results were favorable across different glaucoma subtypes (including POAG, PAC, NTG, OHT), severities, and surgeons, thereby underscoring the real-world relevance and efficacy of iStent inject implantation for glaucoma treatment.