The polyanionic form, commonly referred to as hyaluronan, is a visco-elastic polymer found in the aqueous and vitreous humour of the eye and in the fluid of articulating joints.

Mechanical protection for tissues (iris, retina) and cell layers (corneal, endothelium, and epithelium) are provided by the high viscosity of the solution.

In facilitating wound healing, it is thought that it acts as a protective transport vehicle, taking peptide growth factors and other structural proteins to a site of action.

[2] When used in ophthalmological procedures, sodium hyaluronate may cause postoperative inflammation, corneal edema or decompensation, and short-term increases in intraocular pressure.

[3][4][5] Thus sodium hyaluronate is used as a viscosupplement, administered through a series of injections into the knee, increasing the viscosity of the synovial fluid, which helps lubricate, cushion and reduce pain in the joint.

[11] In surgical procedures in the anterior segment of eyeball, instillation of sodium hyaluronate its viscoelasticity enables maintenance of a deep chamber during surgical manipulation since the solution does not flow out of the open anterior chamber, allowing for efficient manipulation with less trauma to the corneal endothelium and other surrounding tissues.

Its viscoelasticity also helps to push back the vitreous face and prevent formation of a postoperative flat chamber.

In posterior segment surgery, sodium hyaluronate serves as a surgical aid to gently separate, maneuver, and hold tissues.

[26] The first commercially sold sodium hyaluronate had been developed by Endre Alexander Balazs under the brand name of Healon, manufactured by Pharmacia AB in Sweden in 1980.