Water gradients across bovine cornea.

Twenty-six bovine corneas, 30 micron thick, were sectioned perpendicular to the visual axis. Sections, weighing 10-20 mg, were analyzed for total water content by thermogravimetric analysis and for freezable water content by differential scanning calorimetry. The total water content as well as the free (freezable) water content increase, while the bound (nonfreezable) water content decreases in progressing from epithelium to endothelium. These results are correlated with the distribution of proteoglycans and their water sorptive and retentive capacity in bovine cornea.