Elevated intraocular pressure (IOP) causes structural changes in the optic nerve head in glaucoma patients. IOP reduction is clearly the only available treatment that has been proved to decrease both the risk of disease onset and its progression. Glaucoma surgery is indicated when maximal tolerated medical or laser therapy has failed to lower IOP. Anesthesia techniques for glaucoma surgery include general, retrobulbar, peribulbar, sub-Tenon's, subconjunctival, and topical anesthesia. General anesthesia may be advantageous for glaucoma surgery by avoiding the risks of regional anesthesia besides the total immobility of the patient, possibility to control the intraocular pressure, and the facility to fixate the operated eye. Anesthesiologists should be aware of the systemic side-effects and drug interactions of topical or systemic glaucoma medications. In addition, the effects of the anesthetic manoeuvers and drugs on IOP must be taken into consideration.