ABSTRACT

The procedure was first proposed in the early 1990s by Robert Stegmann, and, based on previous studies of non-penetrating trabeculectomies by Krasnov1 and by Zimmerman et al,2 viscocanalostomy aims to restore the natural outflow pathway by allowing the aqueous to leave the eye through Schlemm’s canal and the episcleral veins. The procedure creates a bypass by which aqueous humor can reach Schlemm’s canal, skipping the impaired trabecular meshwork. This bypass is created by the production of a “chamber” inside the sclera in direct communication both with Schlemm’s canal and with the anterior chamber through the intact Descemet’s membrane; a “window” is formed just anterior to the trabecular meshwork (Fig. 9.1). The aqueous enters the chamber by percolating through the membrane, and leaves it via Schlemm’s canal.