Modified Trabeculectomy With an ESST Versus Conventional SST for Management of Primary Open Angle Glaucoma
Condition: Primary Open-angle Glaucoma
MeSH terms: Glaucoma; Glaucoma, Open-Angle
Study type: Interventional

Summary: 
      -  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%).
    

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.
    

Intervention name(s): SST in group (A); trabeculectomy with ESST in group (B)
Intervention type(s): Procedure; Procedure
Intervention description(s): 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; 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 intervention name(s): subscleral trabeculectomy; conventional trabeculectomy; modified trabeculectomy; extended subscleral tunnel
Allocation: Randomized
Intervention model: Parallel Assignment
Intervention model description: Randomized non-controlled comparative prospective interventional study
Masking: Double (Participant, Outcomes Assessor)
Primary purpose: Treatment
Keywords: subscleral trabeculectomy; extended subscleral tunnel; mitomycinC