Trabeculectomy flow pathway, expained, post op care, pre op care

👁 What is Trabeculectomy?

• A standard glaucoma surgery first described by Cairns in 1968
• Goal: Lower IOP → Protect optic nerve → Preserve vision
• Mechanism: Create a new bypass route for aqueous humor outflow

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💧 Normal Aqueous Outflow

Eye → Trabecular Meshwork (TM) → Schlemm’s Canal (SC)
→ Aqueous Veins (AV) / Intrascleral Plexus (ISP) → Outside

• This is the trabecular outflow system (90% of drainage)
• The rest (10%) is via uveoscleral outflow

 

 

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🛠 Surgical Procedure

1. Conjunctival flap → lifted
2. Partial-thickness scleral flap → dissected
3. Deep scleral opening → removes part of TM
4. Flap closed → controlled drainage into subconjunctival space
   ➡ Filtration bleb is formed

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🌀 Post-op Outflow Routes

RouteDescription

⑤ Around the flap	Main route – bypasses TM
④ Through the flap	Additional outflow path
③ AV/ISP	Minimal role post-op
② Cyclodialysis	Complication-related hypotony
① Schlemm’s canal	Nonfunctional after surgery

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💊 Post-op Eye Drops

Medication TypePurpose

Antibiotic	Prevent infection (e.g. Moxifloxacin)
Steroid	Control inflammation (e.g. Pred Forte, Maxidex)
Cycloplegic	Relax ciliary body, stabilize anterior chamber (e.g. Atropine)

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✅ Summary

• Trabeculectomy removes part of TM to create an alternate drainage route
• Post-op flow mainly occurs around/through scleral flap
• Proper post-op care is essential for long-term success