Swelling and transparency of cornea and sclera as compared with a model system composed of pigskin gelatin and mucoitin sulphate

Effects of Divalent Cations on Bovine Corneal Stromal Swelling Rates

“…As previously reported, 3,5,7,8 stromas bathed in PBS swelled in a nonlinear fashion in all salts studied (Fig. 1, upper graph).…”

“…1 Bullot, 2 Loeven, and Van Walbeek, 3 and Wiley and Fatt 4 earlier reported that corneal stromal swelling and hydration is affected to different extents by different monovalent and polyvalent cations. Bullot found that the larger the cation's valence, the more the inhibition of swelling, and that solutions containing monovalent cations were essentially equal at swelling stromas, while high concentrations of divalent calcium antagonized low concentrations of monovalent cation salts.…”

“…2 Loeven and Van Walbeek showed essentially similar findings but looked at polyvalent anions as well and found no anion dependency on swelling, and no anionic dependency on light transmission with one exception: tripotassium ferricyanide increased transparency relative to other anionic salts, and calcium salts decreased transparency relative to potassium salts, probably by precipitating phosphate. 3 Wiley and Fatt stated that salt solutions containing larger ions tended to reduce corneal thickness when they were held at near normal swelling pressures. 4 The latter findings have not been extensively explored for a better understanding of ionic effects on stromal swelling characteristics, and their experiments did not control for pH.…”

Swelling studies of bovine corneal stroma without bounding membranes.

“…This technique has been used by many workers to preserve the stroma for both experimental studies and lamellar keratoplasty (e.g. van Walbeek & Neumann, 1951;Loeven & van Walbeek, 1954;Hedbys, 1961;Payrau & Pouliquen, 1960).…”

“…Both these parameters are known to affect the magnitude of the swelling (Kinsey & Cogan, 1942;Loeven & van Walbeek, 1954;Pau, 1954;Smelser, 1962). We have interpreted these swelling results with a theory derived on the premise that the Donnan contribution is the major component of the swelling pressure (see Appendix).…”