Analysis of Conjunctival Changes as Indicators for Ab-interno Gelatin Microstent Implantation Surgery Outcomes

NCT04727411 | Completed

• 1 other identifier: HCB/2019/0035
• Study Type: interventional
• Target: 39
• Locations: 1 country
• Sites: 1

Brief Summary

Trabeculectomy and XEN45 gel stent implantation are glaucoma surgeries that creates an aqueous humor (AH) shunt towards the subconjunctival space (filtration bleb). Once the AH reaches the subconjunctival space, it is removed by different paths such as the trans-bleb wall route. For this reason, the conjunctiva is considered an essential structure that may condition the glaucoma filtering procedures outcomes. As part of the inflammatory response, an unbalanced fibrosis during the postoperative period may lead to a bleb cavity scarring and failure; for this reason, bleb massage and antifibrotic injections (i.e., 5-Fluoruracil) are frequently required as part of the postoperative care of these procedures. There have been described several risk factors, such as intraocular pressure (IOP) lowering medications, previous surgical interventions or ocular surface disease that may predispose to an early failure. These preoperative factors fail to aim to predict the surgical outcomes. However, ocular biomarkers may overcome this limitation. There are promising studies that have analyzed the role of in vivo confocal microscopy (IVCM), anterior-segment optical coherence tomography (AS-OCT) and conjunctival cytology impression as clinical tools that may improve the filtration bleb assessment at a cellular level.

Conditions

Glaucoma; Glaucoma Open-Angle Primary

Keywords

Gel stent; Trabeculectomy; In vivo confocal microscopy; Conjunctival impression cytology; Anterior segment optical coherence tomography

Outcome Measures

Primary Outcomes (3)

• In vivo confocal microscopy of the filtering bleb

  Increase of the mean microcysts density (MMD): number of cysts/mm2

  Preoperative to 6 months operative

• Anterior segment optical coherence tomography microscopy of the filtering bleb

  Differences in thickness of the conjunctival epithelial surface and the bleb wall, in micrometers

  Preoperative to 6 months operative

• Conjunctival impression cytology of the filtering bleb

  Increase in the percentage of goblet cells biomarkers

  Preoperative to 6 months operative

Secondary Outcomes (2)

• Intraocular pressure

  Preoperative to 6 months visit, at each follow-up visit

• Glaucoma medications

  Preoperative to 6 months visit, at each follow-up visit

Study Arms (2)

Gel Stent implantation

EXPERIMENTAL

XEN gel stent: a clear cornea incision in the inferotemporal quadrant was performed, injecting the XEN 45 device into the superonasal quadrant using an ab interno approach. Approximately 15 min before inserting the implant, 0.1 ml of a MMC solution (0.01%) was injected into the superior conjunctiva. Both stand-alone and combined phaco-glaucoma procedures were used.

Procedure: XEN45 Gel stent

Trabeculectomy

EXPERIMENTAL

Trabeculectomy: the surgical technique is as follows: retro/peribulbar o subtenon's anesthesia, superior corneal traction suture, phacoemulsification through 2.2 with in-the-bag IOL implantation, a fornix-based conjunctival flap, sufficient but not excessive cauterization, application MMC 0,2 mg/ml for 2 minutes under the conjunctiva, then MMC was washed out with 100 ml of saline solution, then a scleral flap (4x3 mm in the trabeculectomy) is dissected. A sclerectomy with punch and peripheral iridectomy were performed, and suture nylon 10/00 sutures was used to place 3 or 4 stiches in the scleral flap

Procedure: Trabeculectomy

Interventions

XEN45 Gel stent PROCEDURE

XEN Gel stent implantation either combined or as a stand-alone procedure

Gel Stent implantation

Trabeculectomy PROCEDURE

XEN Gel stent implantation either combined or as a stand-alone procedure

Trabeculectomy

Eligibility Criteria

• Age: 18 Years - 90 Years
• Sex: male
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Primary open angle glaucoma
• Written informed consent
• Older than 18 years old

You may not qualify if:

• Patients that don't fully understand the purpose and the postoperative care
• Severe or end-stage glaucoma

Sponsors & Collaborators

• Hospital Clinic of Barcelona: lead

Study Sites (1)

Hospital Clínic - ICOF

Barcelona, 08028, Spain

Location

Related Publications (1)

• Ventura-Abreu N, Molins B, Guerra-Meniconi J, Labay-Tejado S, Porto S, Muniesa MJ, Milla E, Pazos M. Longitudinal analysis of XEN45 gel stent bleb morphology using bleb grading scales, anterior segment-OCT, in vivo confocal microscopy, and impression cytology. Graefes Arch Clin Exp Ophthalmol. 2025 Oct 3. doi: 10.1007/s00417-025-06952-0. Online ahead of print.

  PMID: 41042361 DERIVED

MeSH Terms

Conditions

Glaucoma; Glaucoma, Open-Angle

Interventions

Trabeculectomy

Condition Hierarchy (Ancestors)

Ocular Hypertension; Eye Diseases

Intervention Hierarchy (Ancestors)

Filtering Surgery; Ophthalmologic Surgical Procedures; Surgical Procedures, Operative

Study Officials

• Marta Pazos, MD, PhD

  Hospital Clinic

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Investigator, Glaucoma Department

Study Record Dates

• First Submitted: January 16, 2021
• First Posted: January 27, 2021
• Study Start: January 1, 2021
• Primary Completion: May 31, 2022
• Study Completion: October 17, 2022
• Last Updated: January 9, 2024

Record last verified: 2024-01

Locations

ES (1)