Trial Review

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Trial registered on ANZCTR


Registration number
ACTRN12619001364167
Ethics application status
Approved
Date submitted
18/09/2019
Date registered
4/10/2019
Date last updated
16/04/2021
Date data sharing statement initially provided
4/10/2019
Type of registration
Retrospectively registered

Titles & IDs
Public title
Improving the Function Of XEN (iFOX) Study
Scientific title
XEN gel stent implantation variables and their effect upon efficacy in glaucoma management
Secondary ID [1] 299329 0
Nil
Universal Trial Number (UTN)
U1111-1240-5466
Trial acronym
iFOX
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Glaucoma 314471 0
Condition category
Condition code
Eye 312807 312807 0 0
Diseases / disorders of the eye

Intervention/exposure
Study type
Observational
Patient registry
False
Target follow-up duration
Target follow-up type
Description of intervention(s) / exposure
The greatest risk factor for glaucoma is intraocular pressure (IOP). Management of glaucoma aims to reduce IOP and glaucoma surgery involves increasing the outflow of aqueous humour from the eye to achieve this. XEN gelatin stent surgery delivers a consistent non-inflammatory and flexible stent to form a drainage connection between the anterior chamber of the eye and the subconjunctival space. The fluid from the eye drains out through the stent to form a blister (bleb) in the surrounding tissue which is vital for long term success.

This project will allow the long term collection and analysis of data to help improve patient outcomes. Multiple surgical variables may influence post-operative outcomes and success rates of the surgery. These include the entry position, dimensions of the stent within different parts of the eye and the final position of the stent. Other non-surgical factors which are likely to play a role in terms of surgical success include age, sex, racial sub-type and disease (glaucoma) sub-type. The three major endpoints in terms of judging surgical success rates are IOP reduction, number of pressure lowering medications (eye drops) used and drainage area (bleb) shape and appearance.

This will be a prospective observational study over a 12 month period after XEN surgery. Patients who have already undergone surgery will be asked to participate as well as patients about to undergo surgery.

The first phase will involve collecting all of our currently performed XEN gelatin stent patient data, following informed consent and collating that. Data will be collected from patient records and a local clinical database at the Lions Eye Institute from 19/08/19 - 19/08/2021. We will collect IOP measurements, medication usage, bleb appearance (using a standard grading scale), 5-fluorouracil needling usage and complications on these patients in addition to relevant medical information from the patients’ medical records such as previous procedures. We will also have full demographic record including age, sex, race as well as their diagnostic classification. Patients will be followed for at least twelve months and all of their data concerning variables important for this trial will be entered into a specially modified database. These data will include the baseline demographic disease causation data. They will include the anatomical site of insertion through the angle, length of tube position in the three anatomical sites (anterior chamber, scleral, subconjunctival) as well as position around the limbal circumference in clock hours. Intraocular pressure and medication use data will be collected at baseline pre-operatively, one month, two months, three months, six, then at 12 monthly intervals for analysis. Visual acuity at final visit will be recorded and compared to baseline. The number of 5-fluorouracil injections/needling procedures performed post-operatively within the first twelve months will be recorded.

The 12 month visit will be the most important data collection visit. We will also perform anterior segment optical coherence tomography (OCT) imaging using infrared light of the gel microfistula within the scleral and subconjunctival space so that descriptive measures of the intrascleral portion may be documented as well as exact positioning of the termination of the gel stent within the subconjunctival space be identified (anterior tenon’s, mid-tenon’s, deep tenon’s/episcleral). We will also take slit lamp photographs of the bleb and XEN gelatin stent beneath the conjunctiva. We will use these images to validate our clinical grading scheme recorded directly from the clinic. The Indiana Bleb Grading Scheme specifically details degrees of vascularity, including avascular and cystic changes within the bleb along with bleb leaks, bleb size and height.
Intervention code [1] 315598 0
Diagnosis / Prognosis
Comparator / control treatment
No control group
Control group
Uncontrolled

Outcomes
Primary outcome [1] 321423 0
Post-operative change in intraocular pressure measured by Goldmann applanation tonometry
Timepoint [1] 321423 0
12 months post-operatively
Primary outcome [2] 321424 0
Number of intraocular pressure lowering medications (eye drops) documented in medical records
Timepoint [2] 321424 0
12 months post-operatively
Secondary outcome [1] 374920 0
Bleb size and morphology (composite secondary outcome) based on the Indiana Bleb Grading Scale and documented in medical records
Timepoint [1] 374920 0
12 months post-operatively

Eligibility
Key inclusion criteria
Patients with glaucoma (including primary open angle glaucoma, pseudoexfoliative glaucoma, chronic angle closure glaucoma as well as traumatic, uveitic, ICE and congenital glaucoma) who have undergone XEN gel stent implantation
Minimum age
18 Years
Maximum age
No limit
Sex
Both males and females
Can healthy volunteers participate?
No
Key exclusion criteria
Patients who have undergone glaucoma drainage device surgery (e.g. Baerveldt or Molteno tube) within 12 months following XEN surgery

Study design
Purpose
Screening
Duration
Longitudinal
Selection
Defined population
Timing
Both
Statistical methods / analysis
Multivariate linear mixed modelling (ANOVA) and Kaplan-Meier survival analysis will be used to assess the effect of key independent variables upon the response endpoint variables (IOP, medication use, bleb grading etc). The main demographic explanatory variables will be type of glaucoma, pre-existing ocular surgery, glaucoma severity (mean deviation), sex, age, race. The key study specific explanatory variables to be used will include: antimitotic type and dose, XEN position through angle and within subconjunctiva, orientation, pre and postoperative drugs used and preoperative IOP. The study will require the modification of a specific glaucoma database for subject and data collection.

Recruitment
Recruitment status
Recruiting
Date of first participant enrolment
Anticipated
Actual
19/08/2019
Date of last participant enrolment
Anticipated
30/06/2022
Actual
Date of last data collection
Anticipated
30/06/2023
Actual
Sample size
Target
700
Accrual to date
200
Final
Recruitment in Australia
Recruitment state(s)
WA
Recruitment hospital [1] 14810 0
Lions Eye Institute Day Surgery Centre - Nedlands
Recruitment postcode(s) [1] 28060 0
6009 - Nedlands

Funding & Sponsors
Funding source category [1] 303845 0
Commercial sector/Industry
Name [1] 303845 0
Allergan Inc.
Country [1] 303845 0
United States of America
Primary sponsor type
Other Collaborative groups
Name
Lions Eye Institute
Address
2 Verdun Street, Nedlands WA 6009
Country
Australia
Secondary sponsor category [1] 303977 0
None
Name [1] 303977 0
Address [1] 303977 0
Country [1] 303977 0

Ethics approval
Ethics application status
Approved
Ethics committee name [1] 304358 0
University of Western Australia Human Research Ethics
Ethics committee address [1] 304358 0
35 Stirling Highway, Crawley WA 6009
Ethics committee country [1] 304358 0
Australia
Date submitted for ethics approval [1] 304358 0
05/03/2019
Approval date [1] 304358 0
12/08/2019
Ethics approval number [1] 304358 0

Summary
Brief summary
The greatest risk factor for glaucoma is pressure within the eye. Management of glaucoma aims to reduce eye pressure and glaucoma surgery involves increasing the outflow of fluid from the eye to achieve this. XEN gelatin stent surgery delivers a consistent non-inflammatory and flexible stent to form a drainage connection between the space at the front of the eye and the outside of the eye, just beneath the surface of the clear skin (conjunctiva). The fluid from the eye drains out along the tube to form a blister (bleb) in the surrounding tissue, which is vital for long term success.

This project will allow the long term collection and analysis of data to help improve patient outcomes. Multiple surgical variables may influence post-operative outcomes and success rates of the surgery. These include the entry position, dimensions of the stent within different parts of the eye and the final position of the stent. Other non-surgical factors which are likely to play a role in terms of surgical success include age, sex, racial sub-type and disease (glaucoma) sub-type.

We would like to answer questions surrounding which of these parameters are important in determining XEN stent function, eye health after surgery and pressure reduction. The three major endpoints in terms of judging surgical success rates are eye pressure reduction, number of pressure lowering medications (eye drops) used and drainage (bleb bister) area shape and appearance.

This will be a prospective observational study over a 12 month period after surgery. Patients who have already undergone surgery will be asked to participate as well as patients about to undergo surgery. We will collect clinical data over a 12 month period following patients' XEN surgery during their routine post-operatively clinical reviews.
Trial website
Trial related presentations / publications
Public notes

Contacts
Principal investigator
Name 96674 0
Prof William H. Morgan
Address 96674 0
Lions Eye Institute
2 Verdun Street, Nedlands WA 6009
Country 96674 0
Australia
Phone 96674 0
+61 8 9381 0873
Fax 96674 0
Email 96674 0
[email protected]
Contact person for public queries
Name 96675 0
Dr Jessica Ong
Address 96675 0
Lions Eye Institute
2 Verdun Street, Nedlands WA 6009
Country 96675 0
Australia
Phone 96675 0
+61 8 9381 0873
Fax 96675 0
Email 96675 0
[email protected]
Contact person for scientific queries
Name 96676 0
Dr Jessica Ong
Address 96676 0
Lions Eye Institute
2 Verdun Street, Nedlands WA 6009
Country 96676 0
Australia
Phone 96676 0
+61 8 9381 0873
Fax 96676 0
Email 96676 0
[email protected]

Data sharing statement
Will individual participant data (IPD) for this trial be available (including data dictionaries)?
No
No/undecided IPD sharing reason/comment


What supporting documents are/will be available?

No Supporting Document Provided



Results publications and other study-related documents

Documents added manually
No documents have been uploaded by study researchers.

Documents added automatically
No additional documents have been identified.