TRAB | Glaucoma 2026 – Narayana Nethralaya Eye Foundation

Trabeculectomy

Contraindications / caution :

Active conjunctival inflammation/scarring
Fragile or heavily scarred conjunctiva
Neovascular glaucoma
Patients unlikely to follow up reliably
Extreme myopia (higher hypotony/maculopathy risk).

Antimetabolites preparation

Mitomycin C (MMC) – Subconjunctival Injection

Available: 2 mg vial (powder)

Working concentrations:

0.02% = 0.2 mg/mL → reconstitute 2 mg with 10 mL sterile water
0.04% = 0.4 mg/mL → reconstitute 2 mg with 5 mL sterile water

Usual dose: 0.1 mL of 0.02% (higher risk cases: 0.04%)

Preparation & Administration

Reconstitute as above under strict aseptic conditions.
Safety: MMC is cytotoxic — use gloves, mask, protective gear; dispose as cytotoxic waste.
Draw drug: 0.1 mL with 1 mL syringe + 27–30 G needle.
Anesthetize: Topical proparacaine 0.5% or lignocaine 4%.
Inject:

o Site: Superonasal or superotemporal subconjunctiva (8–10 mm from limbus).

o Inject slowly → raised bleb.

o Apply gentle pressure after withdrawal.

Aftercare: Topical antibiotic; monitor for toxicity (scleral thinning, avascular bleb).

5-Fluorouracil (5-FU) – Subconjunctival Injection

Available: 50 mg/mL (250 mg/5 mL vial)

Usual dose: 5 mg (0.1 mL of 50 mg/mL solution)

Preparation & Administration

Check vial: Verify expiry, clarity, no contamination.
Aseptic technique: Hand hygiene, sterile gloves, mask, clean field.
Draw drug: 0.1 mL (5 mg) using 1 mL syringe + 27–30 G needle.

o Dilute with BSS/NS only if lower concentration needed.

Anesthetize: Topical proparacaine 0.5% or lignocaine 4%.
Inject:

o Site: Superior bulbar conjunctiva (~10 mm from limbus).

o Inject 0.1 mL slowly → form a bleb.

o Withdraw carefully; apply gentle pressure to prevent reflux.

Aftercare: Topical antibiotic; monitor for epithelial toxicity.

Key Note

Handle both drugs aseptically.
MMC is cytotoxic—use full precautions.
Discard unused drug safely.
Re-inject only if scarring/vascularity persists.

Outcomes & Safety

* Trabeculectomy remains the benchmark for achieving low target IOPs and often outperforms MIGS in magnitude of lowering, but carries higher risk of certain complications (hypotony, bleb leak, blebitis).

* MMC increases success but also increases the risk of late thin avascular blebs and related complications — dose and delivery method should be tailored to the patient’s scarring risk.

* Early proactive postoperative management (suture manipulation, needling, prompt leak management) reduces long-term complications and improves success.

Recommended learning resources (articles, texts, videos)

* Medscape / eMedicine – “Trabeculectomy: Overview, Indications, Contraindications” https://emedicine.medscape.com/article/1844332-overview

* EyeWiki – “Trabeculectomy” https://eyewiki.org/Trabeculectomy

* Medscape – “Trabeculectomy With MMC or With Amniotic Membrane Transplant” https://www.medscape.com/viewarticle/850535

* Medscape – “Proactive Postop Care Reduces Complications” https://www.medscape.com/viewarticle/812066

Textbooks

Shaarawy T. Glaucoma: Expert Consult Premium Edition-Enhanced Online Features, Print, and DVD, 2-Volume Set. Elsevier Health Sciences; 2009.
Allingham RR, Damji KF, Freedman SF, Moroi SE, Rhee DJ, Shields MB. Shields textbook of glaucoma. Lippincott Williams & Wilkins; 2012 Mar 28.

Video references