Changes in Corneal Endothelial Cell Density After Transscleral ab Interno Glaucoma Gel Stent Implantation

The objective of this study is to evaluate the change of endothelial cell count after XEN45 in patients with or without cataract operation.

Study Overview

• Status: Completed
• Conditions: Glaucoma; Endothelial Cell Loss, Corneal
• Intervention / Treatment: Device: XEN45

Detailed Description

STUDY OBJECTIVE Corneal endothelial cell loss is a known sequela of glaucoma tube shunt implantation. Big tube shunts show a decrease of endothelial cell count postoperatively (-11.5% after Ahmed glaucoma valves and -12.4% after Molteno shunt 2 years postoperatively). The objective of this study is to evaluate the change of endothelial cell count after XEN45 in patients with or without cataract operation.

PATIENT POPULATION In 140 open angle eyes central endothelial cell counts were recorded preoperatively, before the XEN45 implantation was performed in Dept. Ophthalmology at Paracelsus Medical University Salzburg. XEN45s were already performed in the year 2013-2017 (so up to 5 years) in open angle glaucoma eyes in combination with or without cataract operation. In these eyes central endothelial cell count and central corneal thickness was measured preoperatively and documented in patients records.

STUDY DESIGN A prospective, observational, monocentric trial to evaluate the course of endothelial cell density after the XEN implant. The study will take place in the Dept. Ophthalmology at Paracelsus Medical University Salzburg/SALK.

Up to 140 consecutive patients with preoperatively recorded endothelial cell counts will be summoned to a consecutive endothelial cell count record and measurement of central corneal thickness postoperatively. Informed consents will be obtained from patients, who are interested in participating in the study.

Patients will be assessed for endothelial cell density and the position of the XEN45 measured by anterior segment optical coherence tomography. The distance of the XEN45 to cornea, the angle of the tube, and the tube length in the anterior chamber will be recorded with anterior segment optical coherence tomography. Endothelial cell density will be measured on 3 positions: central, superior-nasal (location of XEN45 implantation), infero-temporal (far away for the XEN45 implant).

OUTCOME PARAMETERS The primary endpoint is the change of central endothelial cell density compared to preoperative data.

Secondary objectives are the differences of supero-nasal and infero-temporal endothelial cell density compared to the central endothelial cell density, and pachymetry compared to preoperative data.

EXAMINATION SCHEDULE Subjects will undergo study visits at the following times: preoperative data (2013-2017) out of patient records, postoperative visit in the year 2018-2020 (1-7 years post XEN45 implantation).

CLINICAL PARAMETERS

The following clinical assessments will be performed at the postoperative examination:

1. Endothelial cell count on different locations of the study eye
2. Central corneal thickness
3. Anterior segment optical coherence tomography (to determine the position of the XEN45)
4. Slit lamp examination of the cornea, anterior segment including gonioscopy (to determine the position of the XEN45), and dilated fundus examination
5. Best corrected visual acuity
6. Measurement of IOP
7. Number and frequency of ocular (glaucoma) medications
8. Ocular symptoms and assessment of complications (especially symptoms, which may be a hint for loss of endothelial cell count)
9. Secondary surgical procedures (if applicable including needlings, lasers, cataract operation, bleb revisions, keratoplasty, secondary IOP lowering procedures, other operations)

• Study Type: Observational
• Enrollment (Actual): 129

Contacts and Locations

Study Locations

• Austria
  • Salzburg, Austria, 5020
    • Dept. Ophthalmology and Optometry Paracelsus Medical University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years and older (ADULT, OLDER_ADULT)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

• Sampling Method: Non-Probability Sample

Study Population

Up to 140 consecutive patients with preoperatively recorded endothelial cell counts will be summoned to a consecutive endothelial cell count record and measurement of central corneal thickness postoperatively.

Description

Inclusion Criteria:

1. Open Angle Glaucoma
2. History past XEN45 implantation with or without combined cataract procedure
3. Available preoperative endothelial cell count data not older than 1 year before XEN operation without any operation between the day of data record and XEN45 operation.
4. Age 18 years or older and of legal age of consent
5. Signed written informed consent
6. Availability, willingness, and sufficient cognitive awareness to comply with examination procedures

Exclusion Criteria:

1. Patients with secondary IOP lowering procedures (excluding SLT, needlings, bleb revisions, YAG lasers, Argon lasers) after XEN implantation will be excluded from analysis, because the secondary IOP lowering procedures may influence endothelial cell count itself. Cataract operations without complications are no exclusion criteria, but have to be recorded.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Endothelial cell count measurment	Device: XEN45; Up to 140 consecutive patients with preoperatively recorded endothelial cell counts will be summoned to a consecutive endothelial cell count record and measurement of central corneal thickness postoperatively.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Endothelial Cell Count Change	The primary endpoint is the change of central endothelial cell density compared to preoperative data.	baseline compared to 1-5 years postoperative

Collaborators and Investigators

• Sponsor: Paracelsus Medical University

Study record dates

Study Major Dates

• Study Start (ACTUAL): January 30, 2020
• Primary Completion (ACTUAL): January 31, 2021
• Study Completion (ACTUAL): April 30, 2021

Study Registration Dates

• First Submitted: September 8, 2020
• First Submitted That Met QC Criteria: September 8, 2020
• First Posted (ACTUAL): September 14, 2020

Study Record Updates

• Last Update Posted (ACTUAL): July 13, 2021
• Last Update Submitted That Met QC Criteria: July 12, 2021
• Last Verified: July 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Eye Diseases; Postoperative Complications; Ocular Hypertension; Corneal Diseases; Eye Manifestations; Glaucoma; Corneal Endothelial Cell Loss
• Other Study ID Numbers: 0010152018

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: Yes
• product manufactured in and exported from the U.S.: No