[Endothelium protective effect of hyaluronic acid]

Evaluations on the usefulness of viscous agents in anterior segment surgery. I. The ability to maintain the deepness of the anterior chamber

Maintenance of the deepness of the anterior chamber is necessary to prevent the direct contact of surgical instruments with the corneal endothelium. Therefore, in this study, we measured the ability of viscous agents to maintain the deepness of the anterior chamber in vitro and discussed the correlations between this ability and the viscosity or elasticity of the various viscous agents. A 1% solution of sodium hyaluronate with a molecular weight of 2160 X 10(3) which has the highest viscosity and elasticity showed the best ability to maintain deepness. A 2% solution of methylcellulose with a molecular weight of 86 X 10(3) and a 1% solution of sodium hyaluronate with a molecular weight of 790 X 10(3) were also useful in maintaining the deepness. On the other hand, a 50% solution of sodium chondroitin sulfate with a molecular weight of 30 X 10(3), which has a higher viscosity but a lower elasticity than methylcellulose or sodium hyaluronate with a molecular weight of 790 X 10(3), was unable to maintain sufficient deepness. A 1% solution of sodium hyaluronate with a molecular weight of 250 X 10(3) which has the lowest viscosity and elasticity was completely ineffective for maintaining deepness. These results suggest that the ability to maintain the deepness of the anterior chamber depends on the elasticity of the viscous agent rather than its viscosity.