Modeling the effects of anterior chamber fluid viscosities on intraocular pressure following glaucoma filtering surgery

Abstract

• Background: Hypotonia, flat anterior chamber, and choroidal effusion are not infrequent and undesirable consequences of glaucoma filtering surgery. Methods developed so far to prevent or combat these complications have only been moderately successful. Viscous fluids admixed to the aqueous humor are known to influence fluid dynamics and hence intraocular pressure during variable time intervals following surgery. It was the intention of the authors to develop a mathematical model which predicts the influence of sodium hyaluronate determining the intraocular pressure following injection into the anterior chamber. • Methods: The model is based on first-order approximations and derives from the theory of rheology and fluid dynamics in narrow tubes, and is essentially based on Hagen-Poiseuille's law. • Results: The predictions of the model (to be published in a paper to follow) were verified in experiments on owl monkeys and showed a high degree of predictive power. • Conclusions: One may conclude that sodium hyaluronate, injected once or repeatedly with fine canulas into the anterior chamber, qualifies as an important tool to maintain normal on near-normal intraocular pressure in the immediate and late postoperative phase following surgery.