Schlemm's Canal Development and Implications for Glaucoma Treatment

The Schlemm's canal (SC) is located in the iridocorneal angle of the eye and is critical for regulating intraocular pressure, a contributing factor to glaucoma. SC endothelial cells create the final barrier to aqueous humor (AH) drainage from the eye. SC morphogenesis occurs through a process known as canalogenesis, which combines features of blood vascular and lymphatic development. This reflects the combined lymphatic and blood vascular features of the adult SC. SC development is closely coordinated with the formation of the trabecular meshwork, an adjacent drainage tissue in the angle. Developmental disorders of the SC and trabecular meshwork cause impaired AH drainage, elevated intraocular pressure, and glaucoma. The mechanisms by which the SC develops and controls AH drainage remain partially understood. Recent studies, including single-cell sequencing approaches, are transforming our understanding of the SC, its development, and the genes involved in glaucoma. We highlight current knowledge of SC development, functional morphology, AH drainage past SC endothelial cells, and implications for novel glaucoma treatment strategies.