Needling With Continuous Infusion Into the Anterior Chamber in Eyes with Bleb Failure After PreserFlo MicroShunt Implantation

The PreserFlo MicroShunt (PMS) is a minimally invasive glaucoma device; however, filtration failure due to subconjunctival fibrosis remains a clinical challenge, and the role of bleb needling after PMS implantation remains unclear. This study evaluated the safety and efficacy of bleb needling combined with continuous infusion into the anterior chamber to treat filtration failure after PMS implantation. Four consecutive pseudophakic eyes underwent the procedure, which involved anterior chamber infusion with balanced salt solution and lysing adhesions with a 27-gauge needle under surgical microscopy. No intraoperative complications were observed. During follow-up, repeat needling was required in three eyes, and only one eye required the addition of intraocular pressure (IOP) lowering medication. None of the eyes underwent additional glaucoma surgery, and IOP was lower than that before the PMS implantation. No ocular infections occurred throughout the clinical course. These findings suggest that, although the IOP-lowering effect of needling with continuous infusion into the anterior chamber after PMS implantation is limited compared to trabeculectomy, the technique may help maintain IOP control and avoid reoperation in select cases. The method also allows for safer manipulation by estimating tube position and performing adhesion lysis under controlled irrigation. However, its use is restricted by the need for operating room facilities, resource demands, and limited insurance coverage. While this small case series cannot establish definitive conclusions, the results suggest that bleb needling with anterior chamber infusion may represent a useful alternative to reoperation for PMS filtration failure, which warrants further investigation in larger studies.