Comparison of Bleb Morphology Following Trabeculectomy with and Without Mitomycin-C in primary open-angle glaucoma or primary angle-closure glaucoma

Open Access

Abstract

Introduction: Glaucoma is the second leading cause of blindness worldwide, mainly through primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG). Trabeculectomy is the standard surgery for reducing intraocular pressure (IOP), but scarring can cause bleb failure. Mitomycin-C (MMC) improves outcomes by inhibiting fibroblast growth. Aim of this study: To compare bleb morphology following trabeculectomy with and without MMC in POAG and PACG patients and to correlate morphological features with IOP control, surgical success, and complications. Methods & Materials: This study at the National Institute of Ophthalmology Hospital (NIOH) and Shaheed Suhrawardi Medical college and Hospital, Dhaka, Bangladesh, from April 2024 to March 2025 involved 120 patients with uncontrolled POAG or PACG undergoing trabeculectomy-60 in MMC group and 60 in non-MMC group. The MMC group received 0.4 mg/ml MMC for 3 minutes. Bleb morphology was assessed via slit-lamp and AS-OCT. Postoperative IOP, success, and complications were recorded at 12 months. Results: The MMC group showed better bleb morphology, with more diffuse avascular (63.3% vs 36.7%) and thin polycystic (33.3% vs 6.7%) blebs, while the non-MMC group had more flat vascularized (46.7% vs 3.3%) and encapsulated (10.0% vs 0%) blebs (p=0.004). AS-OCT revealed MMC blebs had thinner walls (80-120 μm vs 110-450 μm), greater height (1.89-2.34 mm vs 1.45-1.92 mm), lower reflectivity (0.7-0.9 vs 0.9-2.6), and larger fluid spaces (0.85-1.42 mm vs 0.04-1.15 mm). The MMC group achieved greater IOP reduction (57.1% vs 35.8%, p<0.001), higher success rates (70.0% vs 30.0%, p<0.001), and had lower bleb fibrosis (3.3% vs 36.7%, p<0.001). Conclusion: MMC-augmented trabeculectomy yields better bleb morphology, diffuse, avascular, thin, polycystic, leading to superior IOP control, higher success, and less fibrosis than conventional surgery. Low-dose, short MMC use is safe and effective in primary glaucoma.