Hydrostatic pressure effects on deswelling of de-epithelialized and de-endothelialized corneas

The effects of varying hydrostatic pressure on the thinning rate of preswollen de-epithelialized or de-endothelialized corneas has been determined in the specular microscope. The appropriate membrane was removed, the cornea given access to Ringer to swell, and then fluid exchange at that surface blocked with oil. De-epithelialized corneas thin more slowly as hydrostatic pressure on the posterior surface is increased, until fluid movement ceases at 60 to 70 mm. Hg. Fluid movement can occur, therefore, against a considerable hydrostatic pressure. De-endothelialized corneas thin at a higher rate as hydrostatic pressure is increased; this effect is probably a mechanical one with increasing pressure forcing fluid out across the epithelium.