The swelling of cornea in bank cultivation. The role of barriers and peripheral edge.
The swelling of a rabbit cornea in organ culture is caused by influx of fluid via the surface. Data regarding the weight increase rates during the first 4 h of corneal buttons with different diameters, have been used to calculate the net influx per mm2 per h via the anterior + posterior surfaces on one hand, and via the peripheral edge on the other hand. In fresh corneas the contribution to the corneal swelling, of the net fluid uptake via the anterior + the posterior surfaces, is negligible. The influx via the peripheral edge is about the same in fresh and freeze treated buttons. For freeze treated corneas, the resistance for fluid transport via the anterior + posterior surfaces seems to be 4 times higher than the resistance for transport via the peripheral edge. This result indicates that the Descemet's membrane and the Bowman's layer may have some barrier effect. An alternative or supplementary explanation is that, at least in swollen corneas, there may be reduced resistance to fluid flow along the corneal plane as compared with the flow vertical to this plane.