A medical shunt used in the treatment of glaucoma to reduce intraocular pressure [IOP], Glaucoma Valves have evolved since first introduced in Cape Town in the mid- 60s. Several varieties of devices for patients who have not responded to maximal medical therapy, with previous surgical procedures proven to not be positive or in cases where usual drainage surgery is unlikely to be successful.
The Ahmed Glaucoma Valve implant and its predecessor the Baervedt Tube Shunt are the leading medical devices for this type of glaucoma surgery. Also, pressure ridge Molteno Glaucoma Valves can be recommended for patients with 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.