Antifibrotic Agents: MMC and 5-FU

Subconjunctival fibrosis is the main cause of trabeculectomy failure. Mitomycin C (MMC, 0.2–0.4 mg/mL for 1–3 minutes) inhibits fibroblast proliferation and is applied under the conjunctiva during surgery. It significantly lowers IOP and improves long-term success, but increases the risk of thin-walled blebs, hypotony, and bleb-related infection. 5-Fluorouracil (5-FU) may be injected post-operatively into a failing bleb. The choice of agent and dosage is tailored to each patient’s risk profile.

Surgical Outcomes

Success rates are approximately 85–90% at one year and 70–75% at five years with MMC. Target IOP is usually less than 15 mmHg for moderate glaucoma and less than 12 mmHg for advanced disease. Trabeculectomy achieves greater IOP reduction than any minimally invasive glaucoma surgery (MIGS) procedure and remains the preferred surgery for advanced glaucoma requiring very low pressures.

Complications and Post-operative Management

Early complications include hypotony (IOP too low), shallow anterior chamber, choroidal detachment, and hyphema. Late complications include cataract progression, bleb leak, blebitis (bleb infection), and endophthalmitis (rare but serious). Post-operative management includes digital massage to maintain bleb function, laser suture lysis (weeks 3–6) to titrate IOP, and needling with 5-FU injection for failing blebs. Patients are followed closely for the first 6–8 weeks and then at regular intervals lifelong.