The invention relates to a method and a device for treatment of glaucoma, wherein by means of an elongated catheter provided with a distal portion and a proximal portion, a tube-shaped implant is inserted and released in a Schlemm's canal with two opposite openings exposed by an incision and a folded up scleral flap. In a first phase, the distal portion inserted into the Schlemm's canal through the first opening, while a fluid or gaseous medium is injected at the same time, and exited through the second opening, which is, in circumferential direction, oppositely located. The implant detachably disposed at the protruding distal portion and, in a second phase, inserted, in circumferential direction, into the expanded Schlemm's canal up to the first opening. Subsequently, the distal portion, which protrudes from the first opening, is detached from the implant and, together with the catheter, removed.