Xen Gel Stent: efficacy, safety and filtering bleb analysis at one year

ISRCTN ISRCTN18170221
DOI https://doi.org/10.1186/ISRCTN18170221
Secondary identifying numbers 1.0
Submission date
26/02/2017
Registration date
09/03/2017
Last edited
12/07/2017
Recruitment status
No longer recruiting
Overall study status
Completed
Condition category
Eye Diseases
Prospectively registered
Protocol
Statistical analysis plan
Results
Individual participant data
Record updated in last year

Plain English summary of protocol

Background and study aims
Primary open angle glaucoma is a condition where the fluid in the eye cannot drain properly, which increases the pressure inside the eye and puts pressure on the optic nerve, which connects the eye to the brain. This can lead to loss of vision. This study is testing the XEN Gel Stent, a new device for the surgical treatment of glaucoma. This device is a tiny tube that is implanted into the eye to reduce the pressure by allowing fluid to drain to a small reservoir (bleb) just under the eye surface. The aim of this study is to assess the effectiveness and safety of the XEN Gel Stent and to investigate the bleb both clinically and using hi-tech methods in order to see if any parameter could guide the surgeons in obtaining better results.

Who can participate?
Patients age 20-70 with primary open angle glaucoma who cannot get their intraocular (eye fluid) pressure sufficiently low on between one and four anti-glaucoma medications

What does the study involves?
All patients undergo implantation of the XEN Gel Stent. Patients who have cataracts also undergo cataract surgery at the same time. The bleb is assessed using a microscope and a scan of the eye at 1, 3, 6 and 12 months after the operation. Safety is assessed by recording any adverse events (side effects) and loss of vision.

What are the possible benefits and risks of participating?
The potential benefits are to be free of or to reduce the burden of taking anti-glaucoma drugs. The risks are minimal although little is known on the long-term effectiveness of the device.

Where is the study run from?
University of Torino (Italy)

When is the study starting and how long is it expected to run for?
January 2014 to August 2015

Who is funding the study?
University of Torino (Italy)

Who is the main contact?
Dr Antonio Fea
antoniomfea@gmail.com

Contact information

Dr Antonio Fea
Public

Eye Clinic
University of Torino
Via Juvarra 19
Torino
10100
Italy

ORCiD logoORCID ID 0000-0002-6551-6054
Phone +39 (0)115 661 566
Email antoniomfea@gmail.com

Study information

Study designProspective interventional non-randomised study
Primary study designInterventional
Secondary study designNon randomised study
Study setting(s)Hospital
Study typeTreatment
Participant information sheet No participant information sheet available
Scientific titleXen Gel Stent implantation in patients affected by primary open angle glaucoma: safety, filtering bleb analysis, intraocular pressure and glaucoma medication use variations within one year
Study objectivesXen Gel Stent is a new and promising minimally invasive glaucoma surgery that creates a filtering bleb in the subconjunctival space and attempts to avoid the major complications related to standard filtering surgery. Safety and efficacy outcomes at one year after stent implantation in primary open angle glaucoma patients (as a solo procedure or combined with cataract surgery) have been poorly reported till now. Moreover, a filtering bleb assessment using different techniques (i.e. OCT and in vivo confocal microscopy) has never been provided.
Ethics approval(s)Ethics Committee Ophthalmic Hospital Turin, January 2014, ref: MS-001
Health condition(s) or problem(s) studiedPrimary open angle glaucoma, cataract
InterventionPatients underwent implantation of the Xen Gel Stent (AqueSys Inc, Aliso Viejo, CA, USA), a minimally invasive glaucoma surgery device that creates a subconjunctival filtering bleb through an ab interno approach. In some cases (i.e. patients with concurrent age-related cataract) cataract surgery was performed at the same time. Biomicroscopy, in vivo confocal microscopy (IVCM) and anterior segment OCT (AS-OCT) were used to assess bleb morphology at 1, 3, 6 and 12 months postoperative. Safety was determined by the incidence of adverse events, loss of best corrected visual acuity (BCVA), Humphrey visual field, and endothelial cell count.
Intervention typeDevice
Pharmaceutical study type(s)
Phase
Drug / device / biological / vaccine name(s)
Primary outcome measure1. Intraocular pressure, measured using Goldmann applanation tonometry (GAT) at baseline, 1 day, 7 days, 1, 3, 6, 9 and 12 months
2. Visual acuity, measured with the standard ETDRS charts at baseline, 1 day, 7 days, 1, 3, 6, 9 and 12 months
3. Incidence of adverse events, measured using a pre-built questionnaire at baseline, 1 day, 7 days, 1, 3, 6, 9 and 12 months
4. Visual field, measured using Humphrey 24-2 at baseline and 12 months
5. Endothelial cell count, measured using Konan Cell Check XL at 1, 3, 6 and 12 months
Secondary outcome measuresBleb morphology, assessed using AS OCT (RTVue-100, Optovue) and in vivo confocal microscopy (HRTII/Rostock Cornea Module) at baseline, 1, 3, 6 and 12 months
Overall study start date01/01/2014
Completion date31/08/2015

Eligibility

Participant type(s)Patient
Age groupAdult
Lower age limit18 Years
SexBoth
Target number of participants11
Key inclusion criteria1. Patients with a diagnosis of POAG with uncontrolled IOP (defined as ≥18 mm Hg and ≤33 mm Hg on between one and four anti-glaucoma medications)
2. A healthy and mobile superior bulbar conjunctiva
3. Age 20-70
Key exclusion criteria1. Previous corneal and glaucoma surgery
2. Diagnosis of glaucoma other than POAG
3. Corneal opacities
4. Ocular diseases other than glaucoma
Date of first enrolment12/06/2014
Date of final enrolment20/12/2014

Locations

Countries of recruitment

  • Italy

Study participating centre

Ospedale Oftalmico
Dipartimento di Scienze Chirurgiche - Clinica Oculistica
V. Juvarra 19
Turin
10122
Italy

Sponsor information

University of Torino
University/education

Eye Clinic
Via Juvarra 19
Torino
10100
Italy

ROR logo "ROR" https://ror.org/048tbm396

Funders

Funder type

University/education

University of Torino

No information available

Results and Publications

Intention to publish date09/03/2018
Individual participant data (IPD) Intention to shareYes
IPD sharing plan summaryOther
Publication and dissemination planPlanned publication in a peer reviewed journal
IPD sharing planThe datasets generated and analysed during the current study will be included in the subsequent results publication

Editorial Notes

12/07/2017: Internal edit.