The Residency Report: PreserFlo microshunt vs trabeculectomy—five-year trial insights

In this installment of The Residency Report—a partnership between Ophthalmology Times and the Department of Ophthalmology at the New York University (NYU) Grossman School of Medicine in New York, New York—NYU ophthalmology resident Preeya Mehta, MD, hosts a journal club discussion on the surgical management of glaucoma. Mehta is joined by Jonathan S. Williams, MD, a glaucoma attending at NYU, and guest Louis R. Pasquale, MD, Chair of Ophthalmology at Mount Sinai Hospital in New York.

The discussion focuses on a 3-year observational extension of a 2-year randomized trial comparing the PreserFlo MicroShunt with trabeculectomy, with an emphasis on long-term safety and effectiveness outcomes.¹ The panel addresses key clinical questions regarding ideal patient selection, expected intraocular pressure (IOP) targets, and how the device may fit into the current glaucoma surgical treatment paradigm.

Pasquale notes that the 5-year data provide a valuable window into long-term outcomes and suggest that the device can be effective for patients with target pressures around 15 mm Hg, emphasizing that not all patients require single-digit IOPs. The panel contrasts the device with trabeculectomy, highlighting that microshunts occupy a distinct role in practice and may require adjunctive medications, underscoring the importance of preoperative counseling.

Surgical technique, mitomycin C, and the learning curve

The conversation also explores surgical technique and mitomycin C dosing, with Pasquale noting that the study’s concentration of 0.2 mg/mL was appropriate given the moderate severity of glaucoma in the study population and the need to balance efficacy with late-onset complications such as conjunctival retraction or extrusion. The panel discusses the learning curve associated with new surgical procedures and anticipates that outcomes may evolve as surgeons gain experience and share best practices.

A central theme is the continued role of trabeculectomy, which the panel agrees remains the only procedure capable of reliably achieving single-digit IOPs, despite its higher risk profile and technical demands. The device may be positioned as a less invasive option that may serve as an intermediate step before glaucoma drainage devices, with the advantage of preserving surgical real estate for future interventions.

Looking forward, the panel emphasizes the importance of longer-term data beyond 5 years to understand tissue responses such as Tenon’s encapsulation and long-term device performance. They conclude by framing glaucoma surgery as a continuum of tools with finite lifespans, reinforcing the concept of tailoring surgical strategies over time to maintain vision throughout a patient’s life.

Reference

1. Scheres LMJ, Kujovic-Aleksov S, Winkens B, de Crom RMPC, Webers CAB, Beckers HJM. Five-year follow-up with the PreserFlo MicroShunt for open-angle glaucoma. Eye (Lond). 2025;39(8):1540-1546. doi:10.1038/s41433-025-03707-3