Study aims to compare the effectiveness and safety profile of Gonioscopy-assisted Transluminal Trabeculotomy and canaloplasty, in order to find out if one operation is superior to the other. Both procedures are performed in patients with medically uncontrolled open-angle glaucoma. Canaloplasty is a recently newly introduced procedure, which showed encouraging results without antimetabolite usage intra- and postoperatively. Gonioscopy-assisted Transluminal Trabeculotomy is the procedure that aims the same mechanism of aqueous outflow, however is perform with ab interno approach, which comprise it to the minimally invasive glaucoma surgery techniques. Purpose of the study is to compare both surgeries concerning success rate, intraocular pressure, medication burden and complications rate. So far there is no comparison of the Gonioscopy-assisted Transluminal Trabeculotomy and canaloplasty available.