Rheology of the vitreous body: part 3. Concentration of electrolytes, collagen and hyaluronic acid.

The vitreous body from bovine, porcine, and human eyes was analyzed for concentration of selected components. Each vitreous sample was sectioned into anterior, central, and posterior segments. The segments were analyzed for concentration of Ca+2, Cl-, Na+, and K+, as well as of Collagen and Hyaluronic acid. The four electrolytes showed significant differences between species, but no significant regional variations. The two macromolecules showed significant differences with respect to both species and region within the vitreous. Comparison of these results with previously determined rheological values for the three species revealed a number of unexpected results, such as higher polymer concentrations on average being associated with lower values of viscosity parameters. The results are analyzed in terms of possible compositional differences among species and effects of electrolytes on the viscoelastic behavior of the vitreous' macromolecules.