Conventional Non-Penetrating Deep Sclerectomy Versus Modified Subflap Mattress Suture in OAG

The goal of this clinical trial is to learn if modified non-penetrating deep sclerectomy (NPDS) with a sub-flap mattress suture works to treat open-angle glaucoma (OAG). It will also learn about the safety and effectiveness of this modified surgical approach. The main questions it aims to answer are: Does the modified NPDS technique result in significantly lower and more persistent intraocular pressure (IOP) reduction compared to the conventional technique? What is the rate of complete success (IOP 6-18 mmHg without medication) and qualified success (IOP 6-18 mmHg with medication) for both groups? What postoperative complications or medical problems (such as iris prolapse, conjunctival leaks, or IOP spikes) do participants experience? Researchers will compare Modified Deep Sclerectomy with Ahmed's sub-flap mattress suture to standard conventional NPDS to see which technique provides better long-term pressure control. Participants will be randomized into two groups and will: Undergo either the standard NPDS procedure or the modified NPDS procedure using a 10/0 nylon mattress suture. Visit the clinic for at least five scheduled follow-up appointments at 1 week, 1 month, 3 months, 6 months, and 9 months post-surgery. Undergo comprehensive eye examinations at each visit, including Goldmann applanation tonometry for IOP, visual acuity testing, and monitoring for the development of cataracts or other surgical complications.

The surgical protocol for Non-Penetrating Deep Sclerectomy (NPDS) begins with standardized aseptic preparation using 10% and 5% Betadine, followed by peribulbar anesthesia. In the standard Group 1 procedure, a 4 mm x 4 mm superficial scleral flap is created after conjunctival dissection, and Mitomycin-C (0.2 mg/mL) is applied for two minutes to inhibit scarring. The core of the surgery involves dissecting a deeper scleral flap to 90% thickness, unroofing Schlemm's canal to expose the trabeculo-descemet's membrane (TDM) and allow for aqueous percolation. The deep flap is then excised, the superficial flap is sutured with 10/0 nylon, and the conjunctiva is closed with watertight 7/0 Vicryl sutures. For Group 2, the standard NPDS steps were followed until the excision of the deep scleral flap, at which point a specific mattress suture modification is introduced. Utilizing the Abdel Rahman and Habib technique, a 10/0 nylon suture is threaded through the sclera 2 mm lateral to the flap borders in an anteroposterior and postero-anterior fashion, creating a mattress configuration beneath the superficial flap to maintain the filtration space. Postoperatively, both groups follow a strict regimen of topical moxifloxacin and prednisolone acetate, which is tapered over six weeks, alongside a five-day course of oral ciprofloxacin to prevent infection and manage inflammation.