Ab Interno Gelatin Stent With Mitomycin C Using Targeted Supra-tenon's Placement

Glaucoma Clinical Trial

Official title:

Ab Interno Gelatin Stent With Mitomycin C Using Targeted Supra-tenon's Placement

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT04454138
• Other study ID #: 955
• Status: Completed
• Start date: June 25, 2019
• Est. completion date: April 20, 2020

Study information

• Verified date: August 2020
• Source: Prism Eye Institute
• Contact: n/a
• Is FDA regulated: No
• Study type: Observational

Clinical Trial Summary

The Xen-45 gelatin microstent is a novel, bleb-forming microinvasive glaucoma surgery (MIGS). Despite demonstrating similar efficacy and safety to trabeculectomy (traditional surgery), the Xen-45 gelatin microstent continues to suffer from occasional surgical failure due to fibrosis of the filtering bleb, and obstruction of the stent. During surgery, placement in a surgery known as supra-tenon's space is believed to maximize aqueous outflow, while preventing obstruction, limiting fibrosis of the bleb, and promoting long-term patency. Despite the theoretical merits, long-term data of outcomes after targeted supra-tenon's placement is needed to fully assess its potential in improving Xen-45 microstent outcomes.

Description:

The Xen-45 gelatin microstent (Allergan, Dublin, Ireland) is a novel, bleb-forming microinvasive glaucoma surgery (MIGS). Creation of a filtering bleb through the gel stent and under the conjunctiva lowers intraocular pressure (IOP) by bypassing the natural outflow pathway of aqueous. A recent retrospective cohort study showed comparable safety and risk of failure to trabeculectomy. Amongst the main advantages of this device is the ability to create a bleb without dissecting and disrupting tissue, thus decreasing the amount of wound healing and potentially limiting bleb failure. However, despite demonstrating similar efficacy and safety to trabeculectomy,2 the Xen-45 gelatin microstent continues to suffer from occasional surgical failure due to fibrosis of the filtering bleb, and obstruction of the stent. Although antimetabolites, such as mitomycin C, have decreased reactionary wound healing that can result following surgery, fibrosis may still occur, especially when the components of the Xen-45 gelatin microstent are in close proximity to the fibroblastic structures of tenon's fascia.Tenon's capsule resembles a sponge-like layer with multiple adhesions to the overlying conjunctiva and underlying episclera. Implantation of the XEN within this space creates a higher risk of obstruction and subsequent failure. To ensure the lowest potential for occlusion, bleb scarring, and failure, one must ensure careful placement of the device in the subconjunctival space, avoiding intra-tenon's placement. Placement in the supra-tenon's space is believed to maximize aqueous outflow, while preventing obstruction, limiting fibrosis of the bleb, and promoting long-term patency. Despite the theoretical merits, long-term data of outcomes after targeted supra-tenon's placement is needed to fully assess its potential in improving Xen-45 microstent outcomes.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 142
• Est. completion date: April 20, 2020
• Est. primary completion date: April 20, 2020
• Accepts healthy volunteers: No
• Gender: All
• Age group: 30 Years to 90 Years

Eligibility

Inclusion Criteria:

• Patients aged 30-90 with primary or pigmentary/pseudoexfolliative open angle, primary closed angle, or combined mechanism glaucoma with IOP of 18-40 mmHg on maximum tolerated medical therapy who received a gelatin stent with MMC at Prism Eye Institute from June 2012 to August 2019.

Exclusion Criteria:

• Other forms of glaucoma

• Prior incisional glaucoma surgery

• CPC

• Prior corneal graft (PKP, DALK, DSAEK, DMEK).

Related Conditions & MeSH terms

• Glaucoma

Intervention

Device:
• XEN-45 gelatin microstent
Placement either in the subconjunctival space or supratenon's area

Locations

Country	Name	City	State
Canada	Prism Eye Institute	Oakville	Ontario

Sponsors (2)

Lead Sponsor	Collaborator
Prism Eye Institute	Allergan

Country where clinical trial is conducted

Canada, 

References & Publications (4)

Conlon R, Saheb H, Ahmed II. Glaucoma treatment trends: a review. Can J Ophthalmol. 2017 Feb;52(1):114-124. doi: 10.1016/j.jcjo.2016.07.013. Epub 2016 Nov 17. Review. — View Citation

Fea AM, Spinetta R, Cannizzo PML, Consolandi G, Lavia C, Aragno V, Germinetti F, Rolle T. Evaluation of Bleb Morphology and Reduction in IOP and Glaucoma Medication following Implantation of a Novel Gel Stent. J Ophthalmol. 2017;2017:9364910. doi: 10.1155/2017/9364910. Epub 2017 Jun 20. — View Citation

Schlenker MB, Gulamhusein H, Conrad-Hengerer I, Somers A, Lenzhofer M, Stalmans I, Reitsamer H, Hengerer FH, Ahmed IIK. Efficacy, Safety, and Risk Factors for Failure of Standalone Ab Interno Gelatin Microstent Implantation versus Standalone Trabeculectomy. Ophthalmology. 2017 Nov;124(11):1579-1588. doi: 10.1016/j.ophtha.2017.05.004. Epub 2017 Jun 7. Erratum in: Ophthalmology. 2018 Mar;125(3):463. — View Citation

Sng CC, Wang J, Hau S, Htoon HM, Barton K. XEN-45 collagen implant for the treatment of uveitic glaucoma. Clin Exp Ophthalmol. 2018 May;46(4):339-345. doi: 10.1111/ceo.13087. Epub 2017 Nov 29. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Postoperative Intraocular Pressure Changes Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Nontargeted Placement.	Mean change in IOP from baseline, IOP thresholds of =6 and =14 (mmHg) on no medications	Post op year 1
Primary	Postoperative Intraocular Pressure Changes Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Nontargeted Placement 2.	Mean change in IOP from baseline, IOP thresholds of =6 and =14 (mmHg) +/- Medications	Post op Year 1
Primary	Postoperative Intraocular Pressure Changes Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Nontargeted Placement 3.	Mean change in IOP from baseline, IOP thresholds of =6 and =17 (mmHg) on no medications	Post op year 1
Primary	Postoperative Intraocular Pressure Changes Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Nontargeted Placement 4.	Mean change in IOP from baseline, IOP thresholds of =6 and =17 (mmHg) +/- medication	Post op Year 1
Primary	Postoperative Intraocular Pressure Changes Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Nontargeted Placement 5.	Mean change in IOP from baseline, IOP thresholds of =6 and =21 (mmHg) on no medications	Post op Year 1
Primary	Postoperative Intraocular Pressure Changes Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Nontargeted Placement 6.	Mean change in IOP from baseline, IOP thresholds of =6 and =14 (mmHg) +/- medications	Post op year 1
Secondary	Number of Participants With Postoperative Complications Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Non-targeted Placement.	Presence or absence of the following complications: i. Starting after POM1: shallow AC w/ iridocorneal touch, any hyphema, corneal edema, wound leak/dehiscience, choroidal effusion, malignant glaucoma, dellen/non-healing epithelial defect, ptosis, diplopia.; ii. At any point: additional glaucoma surgery, loss of light perception vision, vitreous hemorrhage, =2mm hyphema, hypotony maculopathy, implant migration/blockage/exposure/extrusion, macular edema, choroidal effusion/hemorrhage requiring drainage, suprachoroidal hemorrhage, retinal detachment, suture abscess/blebitis/endophthalmitis	Post op year 1
Secondary	Number of Participants With Postoperative Interventions Between Targeted Supratenon's Placement of XEN-45 Gelatin Stent and Non-targeted Placement.	Presence or absence of the following management interventions (not considered complications): bleb needling, AC reformation, suture release, digital ocular compression, use of glaucoma medications, or laser/tpa to blocked ostomy or lumen.	Post op year 1