Report Shows Stent Technique Can Ease Postoperative Management

Ophthalmologist performing cataract surgery
Primary needling at the time of glaucoma microstent insertion is associated with a significant reduction in postoperative needling and clinical visits.

Performing primary needling when an ab interno gelatin microstent is inserted can significantly reduce the need for postoperative needling and other follow-up procedures, according to a study published in Ophthalmology Glaucoma.

“This modification provides a predictable postoperative course with a significant and sustained reduction in both intraocular pressure (IOP) and glaucoma medication requirements with less intense post-operative management,” according to the report.

The retrospective, interventional cohort study looked at 86 consecutive eyes of 72 open-angle glaucoma patients refractory to medical treatment with no prior incisional surgery who underwent insertion of the XEN gel stent (Allergan.) with or without primary needling. The primary outcome measure was the number of eyes that needed postoperative needling; secondary outcome measures included mean reduction in intraocular pressure (IOP), topical glaucoma medication use, complications, reoperations, and number of follow-up clinic visits over 12 months.

Of the total cases, 51 eyes (42 patients, median age 74 years) underwent XEN surgery with primary needling at the time of surgery, while 35 eyes (32 patients, median age 73 years) underwent surgery without routine primary needling. 

Researchers found that eyes receiving routine primary needling had an 84.8% lower rate of postoperative needling (3.9% vs 25.7%, P =.003) and required fewer postoperative clinic visits overall (P =.043). Meanwhile, the median IOP was 18.0 mm Hg and the median number of topical medications was  3.0at baseline. 

By 12 months postoperative, median IOP was 11.0 mm Hg in the primary needling group and 11 mm Hg in the group where primary needling was not routinely performed. Both groups demonstrated a high safety profile. 

Five eyes needed further glaucoma surgery with the insertion of a glaucoma drainage device.

The study’s limitations included the nature of its retrospective design and the fact that medications were not washed out before surgery (both to reflect real-world practice and patient safety), meaning that unmedicated baseline IOP was unknown. The study population was also predominantly White and at a single tertiary practice. Finally, “the decision to perform needling or reinitiate medication was not standardized but instead made at the surgeon’s discretion. However, as there was no difference in the timing of needling, preneedling IOP, or pre-needling medication requirements between the experimental and control groups, it appears the decision to needle was applied consistently,” investigators explain.

Disclosure: One study author declared affiliations with the biotech or pharmaceutical industries. Additionally, the trial itself was supported by Allergan. Please see the original reference for a full list of disclosures.


Kerr NM, Lim S, Simos M, Ward T. Primary needling of the ab interno gelatin microstent reduces postoperative needling and follow-up requirements. Ophthalmol Glaucoma. Published online March 8, 2021. doi:10.1016/j.ogla.2021.02.004