Modified Trabeculectomy With an ESST Versus Conventional SST for Management of Primary Open Angle Glaucoma (POAG)

Modified Trabeculectomy With an Extended Subscleral Tunnel Versus Conventional Trabeculectomy for Management of Primary Open Angle Glaucoma (POAG)

• To evaluate prospectively the surgical outcome in terms of intraocular pressure control, potential advantages, disadvantages, success rate, complications and bleb morphology of this modified trabeculectomy with an extended subscleral tunnel (ESST) in comparison to the conventional subscleral trabeculectomy (SST) in management of uncontrolled primary open angle glaucoma.
• This study will recruit 40 eyes of (40) candidate patients with primary open angle glaucoma (POAG) who are indicated for surgery.
• The candidate patients will be recruited into 2 equal comparative groups. In group (A) 20 eyes (20 patients) who will undergo conventional (SST) with intraoperative mitomycin C (MMC) (0.03%) and group (B); 20 eyes of 20 patients will undergo trabeculectomy with an ESST also with intraoperative adjunctive MMC (0.03%).

Study Overview

• Status: Completed
• Conditions: Primary Open-angle Glaucoma
• Intervention / Treatment: Procedure: SST in group (A); Procedure: trabeculectomy with ESST in group (B)

Detailed Description

• Different surgical procedures were developed and the principle behind them was to establish a fistula between the anterior chamber and the subconjunctival space to permit the aqueous humour to exit the eye.
• Subscleral trabeculectomy has remained the most commonly performed glaucoma surgery to which the newer operations are compared.Although this procedure is very effective in reducing intraocular pressure (IOP) immediately, surgical failure has often been observed over time due to fibrosis of the surgical site and resultant non-filtering bleb. -Improvement of the complication profile and the efficacy of glaucoma filtering surgery is still a major concern for glaucoma surgeons.Therefore, several modifications, combinations, and new techniques of subscleral trabeculectomy have been described.
• In the current study, a fornix-based conjunctival flap will be fashioned in an attempt to encourage more posterior drainage. In this modified trabeculectomy technique, an additional small perpendicular strip of sclera is removed extending from the AC to 2 mm beyond the edge of the scleral flap thus creating an extended subscleral trabeculectomy facilitating aqueous passage into the posterior subconjunctival space.

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Egypt
  • Cairo, Egypt
    • Faculty of medicind

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 40 years to 70 years (Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• Patients with POAG aged from (40- 70) years who are candidate for glaucoma surgery with BCVA ≥ 3/60 to be able to perform visual field testing.
• Non- compliant patients to the medical treatment willing for follow-up visits for at least 6 months post-operatively .

Exclusion Criteria:

• Congenital, traumatic, neovascular, uveitic glaucomas or cases with angle closure glaucoma (ACG) associated with shallow AC.
• Undergoing simultaneous cataract surgery.
• Previous vitreo-retinal surgery including vitrectomy and buckling surgery.
• Other pre-existing ocular cicatrizing diseases.
• Corneal abnormality that precluded reliable applanation tonometry.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Group (A); 20 eyes of 20 patients of uncontrolled POAG administrated intervention will be subscleral trabeculectomy (SST) single surgeon, using retrobulbar anaesthesia with 2% lidocaine, will be performed in all surgeries. Following insertion of a lid speculum, a 10/0 silk bridle suture is inserted at superior limbus if required. In group (A) a conjunctival incision is made at the limbus to create a fornix-based conjunctival flap. A half thickness scleral flap (4 × 4 mm) are created and dissected into the clear cornea. A cellulose microsponge soaked in 0.3 mg/ml MMC solution (Mitomycin-C) is applied to the under surface of the scleral flap over a wide posterior area for 2 ml	Procedure: SST in group (A); group (A) single surgeon, using retrobulbar anaesthesia with 2% lidocaine, will be performed in all surgeries. Following insertion of a lid speculum, a 10/0 silk bridle suture is inserted at superior limbus if required. In group (A) a conjunctival incision is made at the limbus to create a fornix-based conjunctival flap. A half thickness scleral flap (4 × 4 mm) are created and dissected into the clear cornea. A cellulose microsponge soaked in 0.3 mg/ml MMC solution (Mitomycin-C) is applied to the under surface of the scleral flap over a wide posterior area for 2 ml; Other Names: subscleral trabeculectomy; conventional trabeculectomy
Experimental: group (B); 20 eyes of 20 patients of uncontrolled POAG d Administrated intervention will be ESST another longitudinal scleral groove will be created in the center of the deep scleral bed area measured about 1.5 × 6 mm.In both groups, standard trabeculectomy of equal size (two bites aside) is created by a Kelly punch ( 1 mm)	Procedure: trabeculectomy with ESST in group (B); group (B), another longitudinal scleral groove will be created in the center of the deep scleral bed area measured about 1.5 × 6 mm.In both groups, standard trabeculectomy of equal size (two bites aside) is created by a Kelly punch ( 1 mm); Other Names: modified trabeculectomy; extended subscleral tunnel

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
change from baseline intraocular pressure at first day postoperative	mmHg	day one postoperatively
change from baseline intraocular pressure at 4 weeks	mmHg	, 4 weeks.
change from baseline intraocular pressure at 6 weeks Ultrasound bimicroscopy (UBM)	mm Hg	6 weeks post-operatively.
change from baseline intraocular pressure at 3 months	mmHg	3 months postoperatively
change from baseline intraocular pressure at 6 months	mmHg	6 months postoperatively

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
change from baseline best corrected visual acuity (BCVA) at 6 months	logarithm of minimal angle of resolution (log MAR)	at the end of 6 months
extent of filtering bleb area by ultrasound of bio-microscopy (UBM)	width, depth and height of filtering bleb area in millimeter	6 weeks postoperatively

Collaborators and Investigators

• Sponsor: Rehab mahmoud abdelhamid mohamed
• Collaborators: Cairo University
• Investigators: Principal Investigator: Riham S Allam, MD, FRCS GL, Associate Professor of Ophthalmology , Cairo university; Principal Investigator: Karim A Raafat, MD, Professor of Ophthalmology , Cairo university; Principal Investigator: Rehab M Mohamed, MD, lecturer of Ophthalmology , Cairo university

Publications and helpful links

General Publications

• El Sayyad F, Belmekki M, Helal M, Khalil M, El-Hamzawey H, Hisham M. Simultaneous subconjunctival and subscleral mitomycin-C application in trabeculectomy. Ophthalmology. 2000 Feb;107(2):298-301; discussion 302. doi: 10.1016/s0161-6420(99)00097-4.
• Nuijts RM, Vernimmen RC, Webers CA. Mitomycin C primary trabeculectomy in primary glaucoma of white patients. J Glaucoma. 1997 Oct;6(5):293-7.

Study record dates

Study Major Dates

• Study Start (Actual): July 10, 2018
• Primary Completion (Actual): February 28, 2019
• Study Completion (Actual): March 2, 2019

Study Registration Dates

• First Submitted: March 15, 2018
• First Submitted That Met QC Criteria: March 27, 2018
• First Posted (Actual): March 29, 2018

Study Record Updates

• Last Update Posted (Actual): July 19, 2022
• Last Update Submitted That Met QC Criteria: July 18, 2022
• Last Verified: July 1, 2022

More Information

Terms related to this study

• Keywords: subscleral trabeculectomy; extended subscleral tunnel; mitomycinC
• Additional Relevant MeSH Terms: Eye Diseases; Ocular Hypertension; Glaucoma; Glaucoma, Open-Angle
• Other Study ID Numbers: N-38-2018

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED
• IPD Plan Description: study protocol Statistical analysis plan within 6 months after completing the study

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No