Trabecular Micro-Bypass Implant Lowers IOP With or Without Cataract Surgery

Cataract surgery
treatment of a cataract by a surgical method
The trabecular micro-bypass implant is a suitable glaucoma treatment, even without cataract surgery.

The iStent Inject trabecular micro-bypass device safely lowered intraocular pressure (IOP) with or without cataract surgery, according to a study published in Clinical Ophthalmology. The device also decreased medications at 6 months after implantation, the report shows. 

The longitudinal, retrospective study looked at the 6-month results, including performance and safety, of the iStent inject either with or without cataract surgery in 86 eyes of 49 patients (both eyes in 37 patients and 1 eye in 12 patients). Patients underwent iStent inject trabecular micro-bypass implantation either alone (isolated group) or combined with cataract surgery (combined group).  

Primary outcomes included an IOP drop of 20% or more compared with preoperative values (adequate drop) and IOP maintenance between 6 mm Hg and 18 mm Hg (adequate range). Investigators also recorded whether patients needed glaucoma medications by the end of follow-up. Best-corrected visual acuity, adverse events, and secondary surgeries were the safety outcomes measured in the study.

They found that, in the adequate drop analysis, 30.2% of patients had “complete success,” and 37.2% had “qualified success.” For adequate range, 40.7% achieved “complete success” and 39.5% achieved “qualified success.” 

“There was no difference in medication decrease (P =.77) nor IOP reduction (P =.46) between the isolated and combined groups. Safety was generally favorable and similar between groups, with mild transient adverse events that resulted in no sequelae,” according to investigators.

“Results from this retrospective study suggest iStent inject implantation is a suitable treatment option for patients with glaucoma, either as a standalone procedure or in combination with cataract surgery,” they report. “The present study evaluated isolated stent implantation and stent implantation combined with cataract surgery. Both groups demonstrated similar IOP reduction, suggesting that the cataract surgery did not enhance the hypotensive effect caused by isolated stent implant; in other words, the iStent inject device, rather than cataract surgery, appears to be responsible for the IOP reduction.”

The study’s limitations include its retrospective design; patients mostly had mild to moderate glaucoma, so more severe cases weren’t studied; and 6 months might be considered a short time for follow-up overall.

Disclosure: Several study authors declared affiliations with the biotech or pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.


Seixas RCS, Balbino M, Neto AB, et al. Mid-term evaluation of istent inject® trabecular micro-bypass stent implantation with or without phacoemulsification: a retrospective study. Clin Ophthalmol. 2020;14(12):4403–4413. doi:10.2147/opth.S283587.