ABSTRACT
The sodium salt of hyaluronic acid (SH) is a high-molecular-weight biological polymer, made of repeating disaccharide units of glucuronic acid and N-acetyl-ß-glucosamine. This chapter reviews the advances in the use of sodium hyaluronate in ophthalmic therapy, giving the general principles, working hypotheses, and experimental results obtained so far. In a rabbit model, the use of hyaluronidase to increase outflow facility has been suggested to counterbalance the early intraocular pressure rise. SH have several uses in ophthalmic therapy, such as protecting corneal endothelial cells during intraocular surgery, replacing vitreous humor, acting as a tear substitute in the treatment of dry eye, and increasing the precorneal residence time of various drugs. The behavior of endogenous SH in different states of disease has been investigated, and various uses for exogenous SH have been developed. SH prolonged drug delivery when compared with an injection of the same drug in saline solution, but it was less efficient than a collagen implant.
