Numerical simulation of the flow of aqueous humor in the Schlemm's canal

Abstract

Schlemm's canal (SC) is a ring structure responsible for maintaining fluid homeostasis in the anterior chamber of the eye by draining aqueous humor (AH) from the trabecular meshwork (TM) into the collecting channel (CC). Obstruction of the AH flow in this conventional pathway leads to an elevation of intraocular pressure in glaucoma, which is internationally recognized as the most common cause of blindness. Although there are obvious morphological differences between patients and healthy individuals, the AH drainage capacity of SC with specific parameters is difficult to quantitatively evaluate due to the limitations of analyses or experimental technologies. In this paper, the AH flow dynamic features under various SC morphological parameters are studied by numerical simulations of 3D models. The axis length of the SC cross-section and the level of openness are chosen as the main morphological factors according to the clinical data. The flow features, including the velocity, streamline and wall shear stress, are analyzed. This study aimed not only to explore the feasibility of 3D numerical modeling in evaluating the SC drainage capacity, but also to reveal the relationship between SC morphological parameters and the dynamic features of AH drainage.

Keywords: Aqueous humor hydrodynamics; Numerical model; Primary open angle glaucoma; Schlemm's canal.