ABSTRACT
This chapter reviews the techniques and efficacy of various current trabecular bypass micro-invasive glaucoma surgery (MIGS)-type procedures. Gonioscopy must be performed on all patients preoperatively as patients with narrow angles or crowded anterior segments are excluded. Excimer laser trabeculostomyutilizes focal energy from a xenon-chloride pulsed excimer laser delivered through a quartz fiber-optic probe. It aims to create small holes in the trabecular meshwork and inner wall of Schlemm’s canal, thereby “bypassing” the region of highest resistance to outflow. Compared to traditional filtering surgery, MIGS-type trabecular bypass procedures generally achieve modest intraocular pressure-lowering efficacy but have much lower risk profiles. Nonphysiological bleb-forming procedures remain considered as the gold standard of glaucoma surgeries although they continue to have high complication rates and lifetime risks. Trabeculectomy and glaucoma drainage device implantation continue to be the most commonly performed glaucoma surgeries given their well-established efficacy.
