Rheological and Adhesive Properties to Identify Cohesive and Dispersive Ophthalmic Viscosurgical Devices

Abstract

The purpose of this study is to evaluate the usefulness of the rheological properties and adhesive force of ophthalmic viscosurgical devices (OVDs) as parameters for understanding and identifying the surgical behavior of cohesive and dispersive OVDs. The apparent viscosity, and the storage and loss moduli (dynamic rheological parameters) of 50% chondroitin sulfate (CS), 3% sodium hyaluronate (HA), Shellgan (the combination of 3% HA and 4% CS), Opegan (1% HA with a low molecular mass) and Opegan-Hi (1% HA with a high molecular mass) were obtained with a rheometer. The adhesive force of each sample was measured by using a texture analyzer. Opegan-Hi showed a solid-like behavior, while 50% CS showed a fluid-like behavior from their apparent viscosity and dynamic rheological parameters. Shellgan, 3% HA, and Opegan exhibited similar rheological properties and intermediate characteristics between Opegan-Hi and 50% CS, although their respective values were slightly different. Among these OVD samples, the adhesive force was higher in the order of 50% CS > Shellgan, 3% HA > Opegan > Opegan-Hi. The adhesive force of dispersive OVDs tended to be higher than that of cohesive OVDs, which correlated well with the removal times of OVDs from the eye that have previously been reported. In conclusion, we demonstrated that cohesive OVDs and dispersive OVDs have particular rheological and adhesive properties that can be applied to identify both types. These parameters obtained in this study provide useful information for a greater understanding and prediction of the behavior of OVDs in the eye during surgery.

Quantitative Assessment of Ophthalmic Viscosurgical Devices on Visibility, Spreadability, and Durability as Corneal Wetting Agents for the Wet Shell Technique

“…We previously reported that the OVDs tested in this study had specific rheological properties even when they were of the same composition or classification type [14,15]. Here, we clarified the advantages and disadvantages of each OVD for the wet shell technique on the basis of their properties.…”

“…In this study, Opelead, Viscoat, and Shellgan were classified into such a category ( Table 2). We previously evaluated the physical properties of these OVD products and demonstrated that their basic properties were different even though they belonged to the same category [14,15]. We have speculated that the molecular weight (Mw) and concentration of HA, which is the main component of OVDs, have a great influence on rheological properties.…”

“…Although each OVD had a different residual ratio, there was no definite relationship between the retention durability and apparent viscosity. Since these OVDs have different rheological properties [14], intensive studies will be needed to determine how those differences affect retention durability.…”

Evaluation of Rheological Properties of Cohesive Ophthalmic Viscosurgical Devices Composed of Sodium Hyaluronate with High Molecular Weight—2019

“…Frequency Response of Storage Modulus G′ (a), Loss Modulus G″(b), and tand (c)• Opegan-Hi; Hyaluronic acid``TEVA''; ＊ Hyaluronic acid``Kowa''; ▲ Provisc; -Hyaguard; ◆ Opelead-HV; ■ Healon; × Opelead; ＋ Opegan. These rheological parameters of Opegan, Provisc and Opegan-Hi have already been determined 14). …”

“…† Information on the package insert of each OVD product as of March 2019. ‡ Mw of Opegan, Provisc and Opegan-Hi have already been determined 14). …”