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Preserflo MicroShunt Outcomes in Rare and Refractory Glaucoma Entities Compared with Matched Primary Open-Angle

Emil Nasyrov1, Martin Kowalski1, Lasse Wolfram1

  • 1Centre for Ophthalmology, University Hospital Tuebingen, Tuebingen, Germany.

Clinical Ophthalmology (Auckland, N.Z.)
|August 18, 2026
PubMed
Abstract

Insights

The Preserflo MicroShunt (PMS) showed lower efficacy in rare and refractory glaucoma entities (RRG) compared to primary open-angle glaucoma (POAG). Higher bleb revision rates were noted in RRG, particularly in specific subgroups.

Area of Science:

  • Ophthalmology
  • Glaucoma Research
  • Surgical Interventions

Background:

  • Glaucoma management often requires surgical intervention for refractory cases.
  • The Preserflo MicroShunt (PMS) is an option for intraocular pressure (IOP) reduction.
  • Rare and refractory glaucoma entities (RRG) present unique challenges compared to primary open-angle glaucoma (POAG).

Purpose of the Study:

  • To compare the efficacy and safety of the Preserflo MicroShunt (PMS) in patients with rare and refractory glaucoma (RRG) versus primary open-angle glaucoma (POAG).

Main Methods:

  • Retrospective exploratory study comparing PMS implantation in RRG and POAG groups (1:1 matched).
  • Primary outcome: 1-year complete success rate (≥20% IOP reduction, IOP ≤18 mmHg, no medication).
  • Secondary outcomes: Bleb revision and complication rates; Kaplan-Meier analysis and log-rank test used for comparison.

Main Results:

  • The 1-year success rate was significantly lower in the RRG group (56%) compared to the POAG group (71%) (p=0.0079).
  • Subgroup analyses showed significantly lower success in neovascular (NVG), post-traumatic (TG), and primary congenital glaucoma (PCG) subgroups.
  • Bleb revisions were significantly more frequent in the RRG group (58% vs. 41% in POAG).

Conclusions:

  • The Preserflo MicroShunt (PMS) demonstrates reduced efficacy in RRG compared to POAG, mainly due to poorer outcomes in NVG, TG, and PCG.
  • Success rates in aphakic (AG), juvenile open-angle (JOAG), and combined mechanisms glaucoma (CMG) were comparable to POAG.
  • Frequent bleb revisions are a key consideration for RRG, necessitating further validation in prospective studies.
Keywords:
angle-closureaphakiajuvenile open-angle glaucomaneovascular glaucomapost-traumatic glaucomaprimary congenital glaucoma

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