Skip to main content
OpenTrials
Not Yet Recruiting

NCT Number: NCT07531199

Efficacy and Safety of a Releasable Intraluminal Suture Technique to Reduce Hypotony Following Glaucoma Surgery Using the Preserflo Device

Glaucoma is a common and irreversible disease of the optic nerve. It is the second leading cause of blindness worldwide. Glaucoma can be treated with medication, laser therapy, or surgery; the latter is often necessary. Traditional surgeries are invasive and carry a high rate of complications (hypotony, endophthalmitis, cataracts, etc.). Consequently, several types of micro-invasive surgeries (MIGS) and less invasive but effective surgeries, LIGS, have been developed to reduce surgical risks while maintaining effectiveness in lowering intraocular pressure (IOP). PRESERFLO is a drainage system less than 1 mm thick that regulates the outflow of aqueous humor from the eye. It is made of a soft, flexible biomaterial that conforms to the curvature of the eye. This biomaterial does not trigger a negative immune response. PRESERFLO is an example of a recently developed, powerful LIGS procedure (with preliminary results demonstrating efficacy and safety). PRESERFLO is already in use in France (marketing authorization and CE marking obtained) and is covered by social security.

This technique is highly effective in lowering IOP, but it may be associated with hypotony, although less frequently than with trabeculectomy. The use of a releasable suture placed inside the Preserflo to limit drainage and, consequently, reduce the risk of hypotony has been described with good results in preliminary studies. Nevertheless, it is necessary to evaluate the efficacy and safety of this technical modification in a randomized, prospective clinical trial to better understand whether this modification is beneficial for improving the treatment of patients with glaucoma.

Not Yet Recruiting

Trial opening soon.

Get Notified

Key information

Age range

18 year and older

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Primary open-angle glaucoma, pseudoexfoliative glaucoma or pigmentary glaucoma with an indication for glaucoma surgery (defined as uncontrolled intraocular pressure or worsening of visual fields, despite maximum tolerated medical therapy) and an open iridocorneal angle (trabeculum visible on gonioscopy, Shaffer classification grade 3-4)
  • Healthy, mobile conjunctiva (without scarring or adhesions).
  • The indication for glaucoma surgery is defined as uncontrolled IOP or worsening of visual fields despite maximum tolerated medical therapy, and with either a previous failure of trabeculectomy or a risk of failure.
  • Maximum tolerated medical therapy: 3 or more classes of ocular hypotensive treatment, or fewer if there is an allergy or intolerance to the treatment. Visual field defects must be more severe than -3 dB in mean deviation.

Exclusion criteria

  • severe systemic pathologies
  • other ophtalmic pathologies (except cataract)
  • previous intraocular surgery (except cataract)
  • neovascular glaucoma or iris neovascularization
  • pachymetry < 490µm or > 620µm
  • contraindication to PRESERFLO Microshunt

Treatment and study plan

Classical surgery

Procedure

After peritomy, coagulation, and the application of 0.04% mitomycin C (as in a trabeculectomy or any filtration surgery), a scleral tunnel is created 3 mm from the limbus using a 1-mm scalpel designed for this purpose, followed by a 25G needle, which is inserted into the eye parallel to the iris. Next, the Preserflo is inserted into this tunnel, away from the cornea and the iris. The outflow of aqueous humor through the Preserflo is tested by injecting BSS into the anterior chamber. The peritomy is then closed (as in a trabeculectomy).

Intraluminal suture

Procedure

A 9-0 Ethilon suture is inserted into the distal end of the Preserflo to partially occlude the outflow of aqueous humor through this drain, thereby reducing the risk of postoperative hypotony. The other end of this suture is attached to the cornea, forming a loop (which will allow it to be removed later). Next, the Preserflo and the suture are covered with the Tenon's capsule and the conjunctiva, as in the standard technique.

Primary outcomes

  1. Postoperative hypotonia

    Time frame: 12 months after surgery

    IOP ≤ 6 mmHg with vision loss, hypotensive maculopathy, or visible choroidal detachment, as determined during two consecutive visits. Intraocular pressure will be measured using Goldman applanation tonometry

Secondary outcomes

  1. Complete surgical success

    Time frame: 12 months after surgery

    It is defined as a reduction in intraocular pressure of at least 20%, without medication, and without a loss of more than 2 lines of visual acuity, major complications, or the need for further glaucoma surgery

Study contacts

Contact information is provided by the study sponsor or research team.

Marion Mandon, PhD

CONTACT

[email protected]

+33 6 78 27 76 72

Sponsors and collaborators

Lead sponsor

Hôpital Privé de la Baie

Other

Registry information

Acronym: PFLO

Important dates

Study start
2026
Primary completion
2028
Study completion
2029
First posted
Apr 15, 2026
Registry last updated
Apr 15, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

Published trials that share one or more normalized conditions with this study.