Abstract
Surgical procedures are playing an increasingly important role in the treatment of glaucoma. The mechanisms of increased intraocular pressure include structural alterations of tissue within the trabecular meshwork, in the chamber angle, Schlemm canal and the distal collector channels. These changes in the trabecular outflow pathway increase the resistance to the outflow of aqueous humor. Approximately 50-70% of the total outflow resistance in glaucomatous eyes occurs in the trabecular meshwork and 30-50% in Schlemm canal and the collector channels. Various minimally invasive glaucoma surgeries and/or microinvasive bleb-surgeries target these points. Compared to trabeculectomy, which is mainly used for advanced glaucoma and is associated with the use of cytostatics, the achievable pressure reduction is generally somewhat lower. However, the advantage of the newer, more individualized procedures is not only the significantly lower intra- and postoperative complication rate, but also the fact that they can already be used for mild to moderate glaucoma (70 % of all glaucoma patients). This enables efficient glaucoma treatment that can be started earlier, requires only a moderate reduction in pressure and is significantly more effective than glaucoma treatment with medication.