Glaucoma valve

The device works by bypassing the trabecular meshwork and redirecting the outflow of aqueous humour through a small tube into an outlet chamber or bleb.

These are indicated for glaucoma patients not responding to maximal medical therapy, with previous failed guarded filtering surgery (trabeculectomy).

The ExPress Mini Shunt is a newer, non-valved device that was originally designed to provide a direct conduit from the anterior chamber to the sub-conjunctival space or bleb.

Surgical failure occurs due to the ongoing scarring over the conjunctival dissipation segment of the shunt may become too thick for the aqueous humor to filter through.

This may require preventive measures using anti-fibrotic medication like 5-fluorouracil (5FU) or Mitomycin-C (during the procedure), or creating a necessity for revision surgery with the sole or combinative use of biodegradable spacer or collagen matrix implant.