A small implanted device that creates a controlled drainage pathway via a small tube connected to a reservoir plate. Dr. Puja Sheth uses the Ahmed Glaucoma Valve, one of the most established devices of this type, which includes a valve mechanism to help regulate drainage and reduce the risk of the eye pressure dropping too low immediately after surgery.

Often for more complex cases — when previous glaucoma surgery hasn't achieved the needed result, or when trabeculectomy carries a higher risk of complications for a particular eye, for example in some cases of neovascular or uveitic glaucoma. This is generally a decision made after other options have been considered, based on the individual case history.

The device is implanted beneath the eye's surface, with a tube directing drainage and a plate allowing gradual, controlled absorption of the fluid.

Performed as same-day surgery, generally used for more complex cases than MIGS or standard trabeculectomy.

Recovery timelines are broadly similar to trabeculectomy, with regular follow-up to monitor pressure and how the device is functioning. It's designed to remain in place long-term.