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.

7-Year Efficacy and Safety of iStent inject Trabecular Micro-Bypass in Combined and Standalone Usage

“…The outcomes of the current study were also consistent with two of the largest iStent inject studies yet completed in combined [ 20 ] and standalone [ 17 ] cases, respectively. In the 3-year, eight-surgeon pooled cohort from Clement et al [ 20 ], mean IOP reduced to 13.9 mmHg and mean medication burden to 0.48 medications, relatively comparable to the 14.3 mmHg IOP and 0.80 mean medications observed in the Combined subgroup of our cohort at 3 years.…”

“…The outcomes of the current study were also consistent with two of the largest iStent inject studies yet completed in combined [ 20 ] and standalone [ 17 ] cases, respectively. In the 3-year, eight-surgeon pooled cohort from Clement et al [ 20 ], mean IOP reduced to 13.9 mmHg and mean medication burden to 0.48 medications, relatively comparable to the 14.3 mmHg IOP and 0.80 mean medications observed in the Combined subgroup of our cohort at 3 years. Meanwhile, the comprehensive 13-study standalone meta-analysis by Healey et al [ 17 ] reported IOP reductions to the range of 13.0–16.5 mmHg up to 5 years postoperatively, similar to the 14.3–15.3 mmHg IOP range seen in the Standalone subgroup through 7 years in our cohort.…”

Rates of visual field change and functional progression in glaucoma following trabecular microbypass implantation of iStent technologies: a meta-analysis

“…Out of these, eight were successive reports on the same initial cohorts, and a further two reports did not match our retention rates threshold (online supplemental material 1). Ultimately, a total of 15 articles were retained for analysis, with a collective dataset including 1115 eyes 16–31. Seven of these were prospective studies and two were randomised controlled trials.…”

Minimally Invasive Glaucoma Surgery: Latest Developments and Future Challenges

“…In a retrospective study that involved different subtypes of glaucoma (including 28 primary angle closure eyes), combined phacoemulsification and iStent implantation (the second-generation iStent) achieved sustainable IOP and medication reduction for 3 years. 183 A randomized control trial that involved combining phacoemulsification with iStent implantation (first generation) could be safely performed in PACG eyes and resulted in a higher likelihood of achieving medication-free than PACG eyes that underwent phacoemulsification alone at 1 year after the procedure. 184 However, the overall sample size was small and more evidence is required to verify the effectiveness of iStent in PACG eyes.…”

“…Studies have suggested the practicality of performing the procedures when the TM is exposed after lens extraction, although most of these studies were of relatively short-term and small scales. In a retrospective study that involved different subtypes of glaucoma (including 28 primary angle closure eyes), combined phacoemulsification and iStent implantation (the second-generation iStent) achieved sustainable IOP and medication reduction for 3 years 183 . A randomized control trial that involved combining phacoemulsification with iStent implantation (first generation) could be safely performed in PACG eyes and resulted in a higher likelihood of achieving medication-free than PACG eyes that underwent phacoemulsification alone at 1 year after the procedure 184 .…”