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

Primary Purpose

Glaucoma, Glaucoma Open-Angle Primary

Status
Recruiting
Phase
Not Applicable
Locations
Spain
Study Type
Interventional
Intervention
XEN45 Gel stent
Trabeculectomy
Sponsored by
Hospital Clinic of Barcelona
About
Eligibility
Locations
Arms
Outcomes
Full info

About this trial

This is an interventional basic science trial for Glaucoma focused on measuring Gel stent, Trabeculectomy, In vivo confocal microscopy, Conjunctival impression cytology, Anterior segment optical coherence tomography

Eligibility Criteria

18 Years - 90 Years (Adult, Older Adult)MaleDoes not accept healthy volunteers

Inclusion Criteria:

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

Exclusion Criteria:

  • Patients that don't fully understand the purpose and the postoperative care
  • Severe or end-stage glaucoma
  • Patients with prior ocular surgery, excluding uncomplicated phacoemulsification 6 months prior to the inclusion in the study

Sites / Locations

  • Hospital Clínic - ICOFRecruiting

Arms of the Study

Arm 1

Arm 2

Arm Type

Experimental

Experimental

Arm Label

Gel Stent implantation

Trabeculectomy

Arm Description

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.

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

Outcomes

Primary Outcome Measures

In vivo confocal microscopy of the filtering bleb
Increase of the mean microcysts density (MMD): number of cysts/mm2
Anterior segment optical coherence tomography microscopy of the filtering bleb
Differences in thickness of the conjunctival epithelial surface and the bleb wall, in micrometers
Conjunctival impression cytology of the filtering bleb
Increase in the percentage of goblet cells biomarkers

Secondary Outcome Measures

Intraocular pressure
Difference of intraocular pressure, in mm Hg
Glaucoma medications
Difference between the number of glaucoma medications before and after each surgery

Full Information

First Posted
January 16, 2021
Last Updated
March 14, 2022
Sponsor
Hospital Clinic of Barcelona
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1. Study Identification

Unique Protocol Identification Number
NCT04727411
Brief Title
Analysis of Conjunctival Changes as Indicators for Ab-interno Gelatin Microstent Implantation Surgery Outcomes
Acronym
IIT_XEN
Official Title
In Vivo Imaging and Impression Cytology Analysis of Conjunctival Changes as Potential Indicators for Ab-interno Gelatin Microstent Implantation Surgery Outcomes
Study Type
Interventional

2. Study Status

Record Verification Date
March 2022
Overall Recruitment Status
Recruiting
Study Start Date
January 1, 2021 (Actual)
Primary Completion Date
May 31, 2022 (Anticipated)
Study Completion Date
June 30, 2022 (Anticipated)

3. Sponsor/Collaborators

Responsible Party, by Official Title
Principal Investigator
Name of the Sponsor
Hospital Clinic of Barcelona

4. Oversight

Studies a U.S. FDA-regulated Drug Product
No
Studies a U.S. FDA-regulated Device Product
No
Product Manufactured in and Exported from the U.S.
No
Data Monitoring Committee
No

5. Study Description

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.
Detailed Description
Detailed description Hypothesis Conjunctival biomarkers may represent a predictive factor to determine the XEN45 and trabeculectomy surgical success and outcomes A cellular-based analysis may help to predict postoperative pro-fibrotic changes that may lead to an early or mid-term surgery failure, and therefore it could help to improve the postoperative care of the filtering bleb. Objective To evaluate the preoperative and postoperative conjunctival factors that may influence in the surgical outcomes of XEN45 gel stent compared to trabeculectomy using in vivo confocal microscopy, anterior segment optical coherence tomography and conjunctival cytology impression To assess the efficacy of XEN Gel stent and trabeculectomy to predict IOP, based on the morphologic characteristics of the filtering bleb To analyze the needling rate during the postoperative bleb management and the potential correlation to the pre and postoperative conjunctival changes and surgical success outcomes Design Single-center, prospective, simple-blind study Primary outcomes All the outcomes are measured pre and postoperative at each follow-up time In vivo confocal microscopy images: goblet cells density, dendritic cell density and stromal fibrosis Anterior segment optical coherence tomography: wall thickness and epithelium thickness Conjunctival cytology impression: dendritic cells, goblet cells Secondary outcomes Intraocular pressure Number of IOP lowering medications Number of postoperative needling Sample size calculation Based on the most assessed outcome in glaucoma surgeries and the only pilot study aiming to determine a similar outcome, to detect IOP differences between both procedures that may reflect the surgical outcomes of both procedures and therefore reflect the subconjunctival changes, accepting an alfa risk of 0.05 and a beta risk of 0.20 in a two-sided Student's T-test, 40 subjects are necessary in each group to recognize as statistically significant a difference greater than or equal to - 13,38 mm Hg in IOP, with a common standard deviation of 17%. A drop-out rate of 15% has been anticipated. If no drop-out rate is considered, the number of needed subjects is 68 (34 per group) Method Single center, prospective, observational study of primary open angle glaucoma and uncontrolled intraocular pressure, progression of the disease confirmed by visual field examination that require either XEN gel stent implantation or trabeculectomy. Preoperative examinations Medial records including ophthalmic procedures, other ocular diseases, intraocular pressure while on treatment, target pressure, visual field, detailed description of the optic disc, both preoperative and postoperative Glaucoma staging: peripapillary retinal nerve fiber layer, visual field (baseline, 3 moths and 6 months) Ocular biomarkers In vivo confocal microscopy (baseline, 3 moths and 6 months) Conjunctival impression cytology (baseline, 3 moths and 6 months) A specific case report form (CRF) was designed with all variables and data required for the study, including potential complications Surgery. Patients were assigned either to trabeculectomy or XEN stent implantation 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 mitomycin-C (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 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. Post-operative treatment. All patients instilled ofloxacin antibiotic every 6 hours for 1 week, dexamethasone (every 2 hours for 1 month, every 4-6 hours on the second month and tapered during the third month according to surgeon's instructions). Atropine was also used when clinical finds recommended its use. Subconjunctival injections of anti-fibrotic agents (5-FU) and/or bleb needling were allowed and performed at the discretion of the surgeon Statistical analysis Descriptive statistics, including mean and standard deviation for normally distributed variables and median and interquartile range for non-normally distributed variables, previous checked using Shapiro-Wilk test. Logistic regression models to evaluate the correlation with preoperative and postoperative factors and needling rate, surgical success (IOP < 18 mm Hg), and ocular biomarkers. The results will be reported as odds ratio (OR). All the reported values will be considered statistically significant at two-tailed p <0.05

6. Conditions and Keywords

Primary Disease or Condition Being Studied in the Trial, or the Focus of the Study
Glaucoma, Glaucoma Open-Angle Primary
Keywords
Gel stent, Trabeculectomy, In vivo confocal microscopy, Conjunctival impression cytology, Anterior segment optical coherence tomography

7. Study Design

Primary Purpose
Basic Science
Study Phase
Not Applicable
Interventional Study Model
Parallel Assignment
Masking
None (Open Label)
Allocation
Non-Randomized
Enrollment
80 (Anticipated)

8. Arms, Groups, and Interventions

Arm Title
Gel Stent implantation
Arm Type
Experimental
Arm Description
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.
Arm Title
Trabeculectomy
Arm Type
Experimental
Arm Description
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
Intervention Type
Procedure
Intervention Name(s)
XEN45 Gel stent
Intervention Description
XEN Gel stent implantation either combined or as a stand-alone procedure
Intervention Type
Procedure
Intervention Name(s)
Trabeculectomy
Intervention Description
XEN Gel stent implantation either combined or as a stand-alone procedure
Primary Outcome Measure Information:
Title
In vivo confocal microscopy of the filtering bleb
Description
Increase of the mean microcysts density (MMD): number of cysts/mm2
Time Frame
Preoperative to 6 months operative
Title
Anterior segment optical coherence tomography microscopy of the filtering bleb
Description
Differences in thickness of the conjunctival epithelial surface and the bleb wall, in micrometers
Time Frame
Preoperative to 6 months operative
Title
Conjunctival impression cytology of the filtering bleb
Description
Increase in the percentage of goblet cells biomarkers
Time Frame
Preoperative to 6 months operative
Secondary Outcome Measure Information:
Title
Intraocular pressure
Description
Difference of intraocular pressure, in mm Hg
Time Frame
Preoperative to 6 months visit, at each follow-up visit
Title
Glaucoma medications
Description
Difference between the number of glaucoma medications before and after each surgery
Time Frame
Preoperative to 6 months visit, at each follow-up visit

10. Eligibility

Sex
Male
Minimum Age & Unit of Time
18 Years
Maximum Age & Unit of Time
90 Years
Accepts Healthy Volunteers
No
Eligibility Criteria
Inclusion Criteria: Primary open angle glaucoma Written informed consent Older than 18 years old Exclusion Criteria: Patients that don't fully understand the purpose and the postoperative care Severe or end-stage glaucoma Patients with prior ocular surgery, excluding uncomplicated phacoemulsification 6 months prior to the inclusion in the study
Central Contact Person:
First Name & Middle Initial & Last Name or Official Title & Degree
Néstor V Ventura Abreu, MD
Phone
+34697292698
Email
neventura@clinic.cat
Overall Study Officials:
First Name & Middle Initial & Last Name & Degree
Marta Pazos, MD, PhD
Organizational Affiliation
Hospital Clinic
Official's Role
Principal Investigator
Facility Information:
Facility Name
Hospital Clínic - ICOF
City
Barcelona
ZIP/Postal Code
08028
Country
Spain
Individual Site Status
Recruiting
Facility Contact:
First Name & Middle Initial & Last Name & Degree
Nestor Ventura Abreu, MD
Phone
+34 69629268
Email
neventura@clinic.cat

12. IPD Sharing Statement

Learn more about this trial

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

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