Safety and Effectiveness of PreserFlo and XEN Stents With or Without Amniotic Membrane in Glaucoma Surgery

Nova Scotia Health Authority (NSHA)

Status: Not yet enrolling

Conditions: Glaucoma

Treatments: Other: Glaucoma Surgery without Amniotic Membrane; Other: Glaucoma Surgery with Amniotic Membrane

Study type: Interventional

Funder types: Other

Identifiers

NCT07143708

1031327

Details and patient eligibility

About

Glaucoma is one of the leading causes of permanent blindness in the world. It happens when the optic nerve-the connection between the eye and the brain-is damaged. As this damage gets worse, vision is slowly lost.

Glaucoma treatments often begin with eye drops to lower eye pressure. If drops are not enough, surgery may be needed. The type of surgery depends on how advanced the glaucoma is and how much vision has already been lost.

Some glaucoma surgeries, including trabeculectomy, PreserFlo MicroShunt, and XEN Stent, create a new pathway for fluid to drain out of the eye. This helps lower pressure inside the eye.

However, after surgery, the body's natural healing process can sometimes cause inflammation and scarring, which may block the new drainage pathway. If this happens, eye pressure can rise again, and the surgery may not work as well as hoped.

This study is testing whether covering the PreserFlo or XEN devices with amniotic membrane (a safe tissue already used in other eye surgeries) can reduce scarring, improve healing, and lead to better long-term results. Amniotic membrane has already been used safely in many types of eye surgeries. It has been shown to improve healing and reduce scarring in some glaucoma surgeries. But it has not yet been studied in PreserFlo MicroShunt or XEN Stent procedures. The goal is to see if adding amniotic membrane makes the surgery safer and more effective for people with glaucoma.

Full description

Glaucoma is the leading cause of permanent blindness worldwide. Glaucoma is damage to the optic nerve, which sends information from the eye to the brain. This damage causes vision to weaken. Treatment for glaucoma includes the use of medication drops and, ultimately, surgery. The type of surgery is decided by determining the severity and progress of an individual's vision loss.

Certain glaucoma surgeries (including PreserFlo microshunts, and Xen stents) involve creation of an alternative passage for the liquid inside of the eye to be drained. Glaucoma surgery is complex and excessive inflammation and scarring can increase pressure inside the eye and lead to surgical failure. We hope that covering PreserFlo microshunts and Xen stents with amniotic membrane will result in reduced scarring and better pressure outcomes after these surgeries.

Previous research has shown that amniotic membrane is safe for the eye and has improved the outcomes of other similar glaucoma surgeries. However, there are no studies that have investigated whether amniotic membrane is a safe and effective in PreserFlo microshunts, and Xen stents surgeries.

Enrollment: 156 estimated patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

Inclusion criteria

1. Age 18 years and older
2. Patients selected for PreserFlo microshunt surgery and XEN stent alone or in combination with cataract surgery.
3. Ability to comprehend the study procedures

Exclusion criteria

1. Unwilling or unable to give consent
2. Unable to come for scheduled post-operative visits
3. Pregnant or nursing women
4. Previous cyclodestructive procedures, scleral buckling procedures, or presence of silicone oil
5. Conjunctival scarring precluding a glaucoma surgery superiorly
6. Active iris neovascularization or active proliferative retinopathy
7. Vitreous in the anterior chamber for which a vitrectomy is anticipated.
8. Previous trabeculectomy, tube-shunt implantation, or surgeries that shunt aqueous outflow into the subconjunctival space

Trial design

Primary purpose: Supportive Care

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: None (Open label)

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156 participants in 2 patient groups

No Amniotic Membrane Group

Active Comparator group

Description:

Patients receive standard glaucoma surgery (PreserFlo MicroShunt or XEN Stent) without additional covering. The choice between PreserFlo or XEN is not part of the study design-it's determined beforehand by the surgeon as part of regular care.

Treatment:

Other: Glaucoma Surgery without Amniotic Membrane

Amniotic Membrane Group

Experimental group

Description:

Patients receive standard glaucoma surgery (PreserFlo MicroShunt or XEN Stent) with additional covering. The implanted MicroShunt or Stent is covered with an amniotic membrane patch. The choice between PreserFlo or XEN is not part of the study design-it's determined beforehand by the surgeon as part of regular care.

Treatment:

Other: Glaucoma Surgery with Amniotic Membrane