A new meta-analysis of the iStent and iStent inject (Glaukos) found that standalone trabecular micro-bypass glaucoma surgery with the devices is associated with clinically relevant reductions in intraocular pressure.
The focus of the study, which was published in the Journal of Glaucoma, was to systematically identify and quantitatively evaluate the efficacy of iStent devices (iStent and iStent inject) when performed independently of cataract surgery in patients with open-angle glaucoma.
Researchers reviewed literature to identify studies of standalone trabecular micro-bypass glaucoma surgery with iStent devices in patients with open-angle glaucoma. All randomized trials were considered as well as non-randomized studies that included at least 6 months of follow-up or more than 10 eyes. Key efficacy analyses included postoperative IOP and medication use, which were used to evaluate weighted mean differences from baseline, and the proportion of eyes free of ocular medication.
A total of 13 studies were identified including four randomized controlled trials and nine non-randomized or single-arm studies providing data for 778 eyes. In eyes implanted with iStent devices, a weighted mean IOP reduction of 31.1% was observed at 6-12 months. In studies reporting longer-term outcomes (36-48 months or 60 months), the weighted mean IOP reduction was 30.4% and 32.9%, respectively. The pooled weighted mean reduction in intraocular pressure from baseline across all studies at 6-12 months and 36-60 months post-stent implantation was 7.01 mmHg (95%CI: 5.91, 8.11) and 6.59 mmHg (95%CI: 5.55, 7.63), respectively.
Medication burden was reduced by approximately 1.0 medication at 6-18 months, and 1.2 medications at 36-60 months.
Adverse events reported in more than 5% of participants were progression of pre-existing cataract/cataract surgery and loss of best-corrected visual acuity. The researchers noted that these rates were no different to those reported in comparator medical therapy study arms.
“The results from these studies support the independent effect of the iStent trabecular bypass devices on IOP and medication burden over a duration of follow-up of up to 5 years,” the study authors concluded.