Intraoperative Assessment of the Conventional Collector Outflow System as Therapeutic Target

Abstract

The ability to reduce IOP in a glaucomatous eye with minimally invasive surgery that enhances outflow through the patient’s natural aqueous venous channels is nothing short of a miracle. The desire for bleb-less glaucoma procedures along with the recent availability of safe microinvasive glaucoma surgeries (MIGS) has stimulated keen interest in this pursuit.

While ophthalmologists understand trabeculectomy outcomes based on bleb appearance, it is difficult to assess canal procedures because of the inability to easily image the proposed area of improvement, the collector system. At this time, we only have slit lamp observation of aqueous veins and gonioscopy that allow us to correlate canal-based outcomes. This chapter points out methods of intraoperative assessment of canal surgery, especially one newly named observation entitled episcleral venous fluid wave, which hopefully will enhance our understanding of canal anatomy and downstream collector healing. The capability to visualize the aqueous channels in vivo is a milestone in understanding canal-based surgical outcomes.