Implant Lowers IOP on Par With Trabeculectomy for Some Patients

An implant can be just as effective as trabeculectomy in some patients.

The Preserflo® MicroShunt, an 8.5 mm microincisional filtration surgery device, has a rate of success similar to trabeculectomy when 21 mm Hg is the upper target for intraocular pressure (IOP) control, according to a poster presented at the 2022 annual meeting of the American Academy of Ophthalmology (AAO) held in Chicago September 30 to October 3. However, when target IOP is lowered to 17 mm Hg and 14 mm Hg, trabeculectomy has greater success, according to the report.

This 2-year clinical trial ( Identifier: NCT01881425) assessed the max therapy efficacy of patients with uncontrolled IOP (between ≥15 and ≤40 mm Hg) implanted with the MicroShunt device (n=395) compared with those who underwent trabeculectomy (n=132). The study authors defined success as meeting target IOP range (<21, <17 or <14 mm Hg) without glaucoma medication and not failing for protocol-defined reasons.

At year 2, the success rates at achieving each of the 3 target IOPs (<21, <17 or <14 mm Hg) were 52.4%, 45.8%, and 29.6%, respectively, for patients implanted with the MicroShunt, and 59.1%, 56.8%, and 47.0%, respectively, for those who underwent trabeculectomy.

Investigators report differences in the success rates between treatment arms (MicroShunt, trabeculectomy) with 95% CI were -6.7% (-16.5, 3.1), -11.0% (-20.8, -1.1; P =.027) and -17.3% (-26.7, -8.0; P <.001), respectively.

Disclosure: One study author declared affiliations with the biotech, pharmaceutical, and/or device companies. Please see the original reference for a full list of authors’ disclosures.


Panarelli, J, Flowers, B, Lim, M. MicroShunt vs. trabeculectomy complete success rates by target IOP: two-year outcomes of a randomized, multicenter study. Poster presented at: The American Academy of Ophthalmology 2022 annual meeting; September 30 to October 3, 2022; Chicago. Abstract PO162.