Clinical trial NCT04352660: Subconjunctival Versus Direct Mitomycin C in Trabeculectomy
Official title: Subconjunctival Versus Direct Scleral Application of Mitomycin-C in Trabeculectomy
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: PHASE4
Conditions: Open Angle Glaucoma
Keywords: trabeculectomy, mitomycin-C, glaucoma
Lead sponsor: University of California, San Diego
Sponsor class: OTHER
First posted: 2020-04-20
Enrollment: 100
Sex: ALL
Minimum age (years): 18
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: RANDOMIZED
Intervention model: PARALLEL
Primary purpose: TREATMENT

Brief summary: Trabeculectomy is routinely used as a surgical treatment for open angle glaucoma. Success of trabeculectomy is greatly augmented by the use of antimetabolites to inhibit wound healing, specifically Mitomycin C (MMC). MMC can be applied to the eye at various sites, concentrations and times. This study aims to compare the two application routes that are commonly employed: subconjunctival pre-operative injection and intraoperative direct scleral application in terms of IOP lowering effect, bleb appearance and complications.

Detailed description: Trabeculectomy is widely used as a surgical treatment of uncontrolled open glaucoma. Success of trabeculectomy at halting or slowing glaucoma progression primarily relies on the extent of conjunctival and sclera wound healing. The success rates of trabeculectomy increased dramatically with the introduction of anti-metabolites. For more than two decades mitomycin-c (MMC), a chemotherapeutic agent capable of decreasing fibroblast activity and modulating wound healing at the bleb, has been used with trabeculectomy. The complications of MMC are well known and several studies have described various methods of application based on exposure time, dose and surface area. Numerous retrospective and prospective studies have compared the efficacy of MMC applied beneath the conjunctival flap with soaked sponges versus intrascleral application. In 2008, Lee et al. first described an alternative route of application: subconjunctival injection of MMC directly into the intra-Tenon area. Seventy-six eyes with primary and secondary open angle glaucoma underwent trabeculectomy with this approach and were followed for one year post-operatively. Eighty-six percent of eyes achieved an IOP \<21 mm Hg and 57% an IOP\<14 mm Hg at one year without adjunctive drops. Transient complications included hyphema, bleb leak and choroidal detachment. The advantages of injected MMC are primarily in controlling the exact dosage and area of application and reduced surgical time. Lim et al. retrospectively reviewed the outcomes of trabeculectomy in 57 eyes using sponge application directly to the sclera versus intra-tenon injection. IOP was significantly lower in the injection group at 1 month, 1, 2, and 3 years. Trabeculectomy success (IOP\<21mm Hg or IOP \>20% below baseline without medications or additional surgery) was greater in the injection group at 3 years. The sponge group experienced more encapsulated blebs but complication rates were similar in both groups. To date, there have been no prospective studies comparing the IOP-lowering efficacy and safety of intra-tenon injection versus direct scleral application of MMC.

Eligibility criteria: Inclusion Criteria:

* medically uncontrolled glaucoma
* healthy and freely mobile conjunctiva in superior bulbar region

Exclusion Criteria:

* previous incisional glaucoma surgery
* no light perception vision
* pregnant or nursing women
* iris neovascularization or proliferative retinopathy
* iridocorneal endothelial syndrome
* chronic or recurrent uveitis
* steroid-induced glaucoma
* pathologic myopia or refractive error less than -6.00 diopters
* unwillingness or inability to give consent
* inability to return for scheduled protocol visits

Primary outcomes:
measure: Percentage of Participants Achieving Intraocular Pressure Reduction Thresholds
timeFrame: 6 months
Secondary outcomes:
measure: Bleb Morphology
timeFrame: 6 months
measure: Medications
timeFrame: 6 months
measure: Visual Acuity
timeFrame: 6 months
measure: Number of Participants With Surgical Complications
timeFrame: 6 months
measure: Number of Participants Requiring Additional Surgery
timeFrame: 6 months
measure: Postoperative Interventions
timeFrame: 6 months
Other outcomes:
Locations:
Study officials:
affiliation: UCSD
name: Jiun L Do, MD, PhD
role: PRINCIPAL_INVESTIGATOR
affiliation: UCSD
name: Robert N Weinreb, MD
role: PRINCIPAL_INVESTIGATOR
affiliation: UCSD
name: Benjamin Xu, MD, PhD
role: PRINCIPAL_INVESTIGATOR
References: