Abstract:
Background: Glaucoma, characterised by optic neuropathy and elevated intraocular pressure
(IOP), is a leading cause of global blindness, affecting 3.54% of individuals aged 40 to 80.
Trabeculectomy, enhanced with antimetabolites like Mitomycin C (MMC), has long been the
gold standard filtering surgery for glaucoma. The conventional method of MMC application
involves using soaked sponges over the subconjunctival space. However, this approach can
result in complications such as blebitis and foreign-body granuloma due to residual sponges.
Recent research has explored intraoperative MMC injection to improve outcomes and reduce
complications. This study aims to assess the safety and efficacy of a low dose (0.1 mg/ml) of
MMC administered through subtenon injection during trabeculectomy, with a follow-up period
of over 6 months.
Materials and Methods: It is a prospective interventional study on patients who underwent
trabeculectomy with a subtenon injection of 0.1mg/ml of Mitomycin C combined with Small
incision cataract surgery with intraocular lens implantation and were followed up over 6
months. Efficacy was determined in terms of intraocular pressure reduction, bleb architecture
was graded using the Indiana Bleb Appearance Grading System (IBAGS), and safety was
commented upon regarding postoperative complications.
Results: Thirty patients were enrolled, with the majority having primary open-angle glaucoma
(63.33%), while 36.67% had primary angle-closure glaucoma. Baseline intraocular pressure
(IOP) was 31.40 (± 10.38) mmHg. It significantly reduced to 14.60 (± 3.75) mmHg on the first
postoperative day, decreasing to 9.55 (± 1.57) mmHg by the 6th postoperative month (p =
0.001). The percentage reduction in IOP was substantial, 69.57%, by the 6th postoperative visit.
Bleb morphology assessment using IBAGS revealed significant improvements in bleb height,
extent, and vascularity over the 6-month follow-up (p = 0.001). Out of the total patients,93.33% achieved controlled IOP without antiglaucoma medications, while 6.67% required one
medication for IOP control. Complications were minimal, with transient corneal oedema in six
patients and manageable postoperative hypotony in one case.
Conclusion: A sub-tenon injection of MMC effectively reduces intraocular pressure and
promotes favourable bleb architecture, offering a safe and minimally complicated alternative
to the conventional approach. It can be safely considered in high-risk patients as an alternate
route of MMC application during trabeculectomy.
