Glaukos Completes Enrollment in Pivotal U.S. Study of PRESERFLO™ MicroShunt for Advanced Primary Open-Angle Glaucoma
Glaukos Corporation, an ophthalmic pharmaceutical and medical technology company dedicated to developing innovative treatments for glaucoma, corneal disorders, and retinal diseases, has announced the successful completion of patient enrollment in its U.S. 510(k) pivotal clinical study evaluating the PRESERFLO™ MicroShunt. The investigational study is assessing the safety and effectiveness of the minimally invasive glaucoma drainage device in adult patients with primary open-angle glaucoma (POAG) whose disease remains inadequately controlled despite previous medical and surgical interventions.
The milestone represents an important advancement in Glaukos’ clinical development program and moves the company one step closer toward seeking U.S. regulatory clearance for the PRESERFLO MicroShunt. With enrollment now complete, the study enters its next phase, during which investigators will monitor patients over the designated follow-up period to evaluate clinical outcomes, including intraocular pressure reduction, medication use, and overall device performance.
Addressing an Ongoing Need in Advanced Glaucoma Care
Glaucoma remains one of the leading causes of irreversible blindness worldwide, affecting millions of individuals and posing a significant public health challenge. Primary open-angle glaucoma, the most common form of the disease, is characterized by progressive damage to the optic nerve that is frequently associated with elevated intraocular pressure (IOP). Without effective management, the disease can gradually lead to permanent vision loss.
Although prescription eye drops, laser treatments, and various surgical procedures have significantly improved glaucoma management, many patients continue to experience disease progression despite multiple treatment attempts. Individuals who have previously undergone glaucoma surgery yet continue to have uncontrolled intraocular pressure often face limited therapeutic options, making this population particularly challenging to treat.
The PRESERFLO MicroShunt has been developed to address this unmet need by offering a minimally invasive surgical alternative designed to provide sustained intraocular pressure reduction while potentially minimizing some of the complexities associated with conventional glaucoma filtration surgeries.
Innovative Design of the PRESERFLO MicroShunt
The PRESERFLO MicroShunt is an ab-externo glaucoma drainage implant specifically engineered to reduce intraocular pressure by facilitating the controlled drainage of aqueous humor from the anterior chamber of the eye into a subconjunctival bleb.
Unlike traditional filtering surgeries, the device is designed to provide a standardized and reproducible surgical approach while maintaining effective long-term fluid drainage.
Constructed from Glaukos’ proprietary biocompatible material known as SIBS—poly(styrene-block-isobutylene-block-styrene)—the implant measures approximately 8.5 millimeters in length and features a flexible design intended to integrate well with surrounding ocular tissues.
One of the defining characteristics of the device is its planar fin architecture, which helps stabilize positioning within the eye, facilitates tissue fixation during implantation, and assists in minimizing postoperative leakage. These design elements are intended to improve both surgical consistency and long-term clinical performance.
Because SIBS is highly biocompatible and resistant to degradation, the material has demonstrated favorable compatibility within ocular tissues, supporting its use in long-term implantable ophthalmic devices.
A Minimally Invasive Alternative for Complex Cases
Traditional glaucoma filtration procedures, including trabeculectomy and tube shunt implantation, have long served as the standard surgical options for patients with advanced glaucoma. While these procedures can be highly effective at lowering intraocular pressure, they often involve technically demanding surgeries and require intensive postoperative management.
The PRESERFLO MicroShunt has been developed as an alternative surgical approach that combines effective pressure reduction with a streamlined implantation procedure.
Its minimally invasive ab-externo technique allows surgeons to implant the device without creating extensive scleral flaps or requiring the complex tissue manipulation associated with conventional filtration surgery.
Researchers believe this simplified approach may help reduce procedural variability while providing physicians with another valuable treatment option for patients who have exhausted previous medical and surgical therapies.
Enrollment Milestone Marks Significant Progress
The newly completed pivotal study successfully achieved its enrollment target of at least 110 patients across multiple clinical centers located throughout the United States and Canada.
The prospective, multicenter, single-arm clinical trial specifically enrolled adults diagnosed with primary open-angle glaucoma who previously underwent unsuccessful incisional or cilioablative glaucoma surgery and continued to have inadequately controlled intraocular pressure despite ongoing use of pressure-lowering medications.
By focusing on this particularly difficult-to-treat patient population, investigators hope to demonstrate the potential value of the PRESERFLO MicroShunt in addressing an area of significant unmet clinical need.
Completion of enrollment represents an important operational milestone, allowing the study to transition fully into postoperative monitoring and data collection.
Clinical Study Objectives
The pivotal clinical trial has been designed to evaluate both the effectiveness and safety of the PRESERFLO MicroShunt in patients with advanced glaucoma.
The primary effectiveness endpoint focuses on achieving a clinically meaningful reduction in intraocular pressure while avoiding an increased dependence on glaucoma medications.
Specifically, investigators will assess whether patients achieve at least a 20% reduction in mean diurnal intraocular pressure from baseline at 12 months following implantation without requiring an increase in the number of intraocular pressure-lowering medication classes compared with baseline treatment.
In addition to the primary endpoint, investigators will collect comprehensive data on postoperative safety, device performance, adverse events, medication burden, and overall surgical outcomes.
These findings are expected to provide important evidence supporting the potential regulatory review of the device in the United States.
Supporting Future FDA Submission
Glaukos intends to use the clinical data generated from the pivotal study as the basis for a future U.S. Food and Drug Administration (FDA) 510(k) marketing submission.
If the study successfully demonstrates that the device meets its predefined safety and effectiveness objectives, the results could support regulatory clearance, enabling broader availability of the PRESERFLO MicroShunt for eligible glaucoma patients across the United States.
Regulatory approval would significantly expand treatment options for ophthalmologists managing patients with advanced disease who have limited alternatives following previous surgical intervention.
Leadership Perspective
Thomas Burns, Chairman and Chief Executive Officer of Glaukos, described the completion of enrollment as a major milestone in the company’s ongoing commitment to advancing glaucoma care.
He noted that patients with advanced glaucoma who continue to experience elevated intraocular pressure despite prior surgical treatment remain at considerable risk for progressive and irreversible vision loss.
According to Burns, the company believes the PRESERFLO MicroShunt offers an elegant surgical alternative to conventional trabeculectomy and tube shunt procedures by combining a minimally invasive implantation technique with effective pressure-lowering capabilities.
He emphasized that Glaukos remains focused on expanding its comprehensive glaucoma treatment portfolio to address the evolving needs of both physicians and patients throughout every stage of disease management.
Growing Global Clinical Experience
Although the PRESERFLO MicroShunt is still under clinical evaluation in the United States, the device has already received regulatory approval in several international markets where Glaukos holds commercialization rights.
Through its licensing agreement with Santen Pharmaceutical Co., Ltd., Glaukos possesses exclusive rights to develop and commercialize the device in the United States, Canada, Australia, New Zealand, Brazil, and Mexico.
The device is currently commercially available in several of these countries, including Canada and Australia, where adoption among glaucoma specialists has steadily increased.
Physicians in these markets continue to gain real-world clinical experience with the implant, contributing to an expanding body of evidence supporting its long-term safety, effectiveness, and surgical performance.
The growing international experience may provide valuable insights that complement findings from the ongoing U.S. clinical program.
Expanding the Glaukos Glaucoma Portfolio
The PRESERFLO MicroShunt represents another important component of Glaukos’ broader strategy to develop innovative technologies spanning the entire glaucoma treatment continuum.
Over the past decade, the company has played a leading role in advancing minimally invasive glaucoma surgery (MIGS), introducing several technologies designed to reduce intraocular pressure while minimizing surgical trauma.
By developing therapies suitable for patients with mild, moderate, and advanced disease, Glaukos aims to provide physicians with flexible treatment options that can be tailored to individual patient needs throughout disease progression.
The addition of the PRESERFLO MicroShunt has the potential to strengthen this portfolio by addressing patients whose glaucoma remains difficult to control after previous surgical intervention.
With enrollment now complete, investigators will continue postoperative follow-up throughout the study period to assess both short-term and long-term outcomes.
The data collected over the coming months will play a critical role in determining whether the PRESERFLO MicroShunt can successfully meet its clinical endpoints and support regulatory clearance in the United States.
If successful, the device could become an important addition to the glaucoma treatment landscape by offering ophthalmic surgeons another minimally invasive option for managing patients with advanced primary open-angle glaucoma who continue to face elevated intraocular pressure despite previous therapies.
As Glaukos advances the program toward regulatory submission, the company remains committed to delivering innovative ophthalmic technologies that seek to preserve vision, improve patient outcomes, and expand treatment possibilities for individuals living with glaucoma worldwide.
About Glaukos
Glaukos (www.glaukos.com) is an ophthalmic pharmaceutical and medical technology company focused on developing and commercializing novel therapies for the treatment of glaucoma, corneal disorders, and retinal diseases. Glaukos first developed Micro-Invasive Glaucoma Surgery (MIGS) as an alternative to the traditional glaucoma treatment paradigm, launching its first MIGS device commercially in 2012.
In 2024, Glaukos commenced commercial launch activities for iDose® TR, a first-of-its-kind, long-duration, intracameral procedural pharmaceutical designed to deliver 24/7 glaucoma drug therapy inside the eye for extended periods of time. Glaukos also markets the only FDA-approved corneal cross-linking therapy utilizing a proprietary bio-activated pharmaceutical for the treatment of keratoconus, a rare corneal disorder.
Glaukos continues to successfully develop and advance a robust pipeline of novel, dropless platform technologies designed to meaningfully advance the standard of care and improve outcomes for patients suffering from chronic eye diseases.