Glaucoma is a neurodegenerative disease with an accelerated and progressiv retinal ganglion cell loss and concomitant visual field defects. Glaucoma can be treated with eye drops, laser therapy or surgery. Various surgical approaches to lower intraocular pressure are available, amongst which trabeculectomy is the gold standard. Recently minimal invasive glaucoma surgery has been introduced and has become a good alternative to trabeculectomy. Randomized clinical trials investigating the postoperative outcomes of various types of glaucoma surgery are limited.