Glaucoma valve
device surgically inserted in the sclera to maintain normal intraocular pressure
A glaucoma valve is a medical shunt used in the treatment of glaucoma to reduce the eye's intraocular pressure (IOP).
Mechanism
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. The IOP generally decreases from around 33 to 10 mmHg by removing aqueous on average 2.75 microliters/min.
Types
The first glaucoma drainage implant was developed in 1966. Following on the success of the Molteno implant, several varieties of device have been developed from the original, the Baerveldt tube shunt, or the valved implants, such as the Ahmed glaucoma valve implant and the later generation pressure ridge Molteno implants. These are indicated for glaucoma patients not responding to maximal medical therapy, with previous failed guarded filtering surgery (trabeculectomy). The flow tube is inserted into the anterior chamber of the eye and the plate is implanted underneath the conjunctiva to allow flow of aqueous fluid out of the eye into a chamber called a bleb.
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. In this position it was unstable and tended to erode through the conjunctiva. Now the more common use is as a modification of the trabeculectomy procedure, placed under a scleral flap, replacing the sclerostomy step (see trabeculectomy).
The public source identifies “Glaucoma valve” as device surgically inserted in the sclera to maintain normal intraocular pressure. This brief keeps that definition visible, then builds a research path around Glaucoma, valve and device.
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Vocabulary and entity names are the principal evidence signals here, because they determine the precision of every later search. The source revision retrieved here is dated Jul 15, 2026. The linked authority identifier is Q3117462. The first chronological checks are 1966.
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This entry incorporates text from “Glaucoma valve” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.