Long-term Results of the PRESERFLO MicroShunt in Patients With Primary Open-angle Glaucoma From a Single-center Nonrandomized Study

Abstract

Precis: The MicroShunt was implanted in 23 patients with primary open-angle glaucoma (POAG) in a feasibility study. Reductions in intraocular pressure (IOP) and medications were sustained for up to 5 years with no long-term sight-threatening adverse events (AEs).

Purpose: The purpose of this study was to assess the long-term effectiveness and safety of the PRESERFLO MicroShunt (8.5 mm long, 70 µm lumen surgical device, formerly known as the InnFocus MicroShunt) in POAG.

Patients and methods: In a feasibility study (NCT00772330), patients with POAG inadequately controlled on maximum tolerated therapy with IOP ≥18 to ≤40 mm Hg underwent MicroShunt implantation with adjunctive mitomycin C (0.4 mg/mL), alone or in combination with cataract surgery. Years 1 to 3 findings have previously been reported. Endpoints of this extension study included IOP reduction and success at years 4 and 5 (primary), incidence of AEs, medication use, and reoperations.

Results: Mean IOP was reduced from 23.8±5.3 mm Hg at baseline to 12.8±5.6 mm Hg (year 4; n=21) and 12.4±6.5 mm Hg (year 5; n=21). Overall success (with/without medication use) was 87.0% (year 4) and 82.6% (year 5). The mean number of medications reduced from 2.4±1.0 at baseline to 0.8±1.3 (year 5). Common (≥5% of patients) AEs included corneal edema (n=4), transient hypotony (n=4), bleb-related complications (n=3), and device touching the iris (n=3). There were 4 reports of serious AEs and 2 reoperations.

Conclusions: In this extension study, sustained reductions in mean IOP and medications were observed up to 5 years post-MicroShunt implantation. There were no reports of long-term sight-threatening AEs and a low rate of postoperative interventions.

FIGURE 1

Dimensions of the MicroShunt and placement in the eye. Adapted from Batlle et al. Adaptations are themselves works protected by copyright. So in order to publish this adaptation, authorization must be obtained both from the owner of the copyright in the original work and from the owner of copyright in the translation or adaptation.

FIGURE 2

The MicroShunt was placed between the superior and lateral rectus. The dot in the ST quadrant signifies the location of the MicroShunt. IN indicates inferonasal; IT, inferotemporal; OD, oculus dexter; OS, oculus sinister; SN, superonasal; ST, superotemporal.

FIGURE 3

Patient disposition.

FIGURE 4

Mean±SD medicated IOP over 5 years of follow-up. Missing IOP scores were imputed using the last observed IOP score. IOP scores collected after reoperation are excluded. Results at years 1, 2, and 3 have been corrected compared with previously published findings, following reanalysis conducted for this manuscript. IOP indicates intraocular pressure.