In 1968, Cairns described the filtration surgery technique known as trabeculectomy, 1 which, to this day, is still considered by many as the gold standard of glaucoma surgery. Meanwhile, also in the late 1960s, the first tube and plate device was introduced by Molteno 2,3 and was then followed by development of other tube shunt devices, including the Krupin eye disc, 4 the Baerveldt glaucoma drainage implant, 5 and the Ahmed valve. 6 All these filtering procedures share a common goal of creating a nonphysiological fistula or passageway from the anterior chamber to the subconjunctival space, and they have well-established IOP-lowering efficacy.