Assessing the impact of delayed flow in glaucoma surgery

The Effects of Temporary Tube Ligation in Ahmed Glaucoma Valve Surgery

Observational Washington University School of Medicine · NCT05685485

This study is testing if slowing down the flow of fluid after glaucoma surgery can help people have better results and fewer problems afterward.

Quick facts

Study typeObservational
Enrollment152 (estimated)
Ages18 Years and up
SexAll
SponsorWashington University School of Medicine Academic / other
Locations1 site (St Louis, Missouri)
Trial IDNCT05685485 on ClinicalTrials.gov

What this trial studies

This observational study aims to evaluate whether delaying early aqueous flow through the Ahmed glaucoma valve shunt can enhance post-operative outcomes and predictability. Participants will be randomly assigned to receive either a standard Ahmed valve implantation or one with tube ligation to restrict early flow. The study will measure intraocular pressure (IOP) at various intervals post-surgery and collect data on glaucoma medication usage and complications. The goal is to determine if limiting early flow can reduce complications and improve long-term IOP control.

Who should consider this trial

Good fit: Ideal candidates include adults aged 18 and older with inadequately controlled glaucoma or ocular hypertension who are scheduled for Ahmed valve implantation.

Not a fit: Patients with non-functional vision, those unable to provide consent, or those with specific contraindications such as uveitic glaucoma will not benefit from this study.

Why it matters

Potential benefit: If successful, this approach could lead to better surgical outcomes and fewer complications for glaucoma patients.

How similar studies have performed: While this approach is innovative, similar studies have suggested that managing early aqueous flow can positively influence surgical outcomes, indicating potential for success.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Subjects with age at screening ≥ 18 years
* Inadequately controlled glaucoma or ocular hypertension
* Ahmed valve implant as the planned surgical procedure
* Patients with primary glaucomas (Primary Open Angle Glaucoma or Primary Angle Closure Glaucoma) or pseudoexfoliation, pigmentary and traumatic glaucoma with or without a previous failed trabeculectomy or other intraocular surgery.
* Primary tubes included
* Investigators to recruit consecutively all eligible patients from their clinics.
* Capable and willing to provide consent

Exclusion Criteria:

* Subjects with NLP vision
* Subjects unable/unwilling to provide informed consent
* Unavailable for regular follow up
* Previous cyclodestructive procedure
* Prior scleral buckling procedure or other external impediment to drainage device implantation
* Presence of silicone oil
* Vitreous in the anterior chamber sufficient to require a vitrectomy
* Uveitic glaucoma
* Neovascular glaucoma
* Nanophthalmos
* Patients with pathology that may cause elevated episcleral venous pressure
* Procedure combined with ocular surgery other than cataract surgery (i.e. combined tube-cataract surgery is okay)
* Any abnormality other than glaucoma in the study eye that could affect tonometry.

Where this trial is running

St Louis, Missouri

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Glaucoma EyeAhmed Glaucoma Valve Implantation
Last reviewed 2026-06-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.