Drainage devices (aqueous shunts – AS) in glaucoma surgery have been improved within last 40 years. They are used in refractory glaucoma, caused by: conjunctival scarring after previous filtrating surgery, abnormalities of the irido-corneal angle, neovascular and inflammatory glaucoma, presence of corneal grafts or keratoprosthesis, previous vitreoretinal surgery. AS consist of a silicon tube (implanted into the anterior chamber) and a plate, made of silicone or polypropylene (explant, sutured between rectus muscles). Fibrous bleb, surrounding explant after some weeks is a filtration reservoir. The results of AS surgery are comparable to trabeculectomy with mitomycin C; there are no differences between results of different AS models.