Changes in the swelling pressure of the corneal stroma with time, hydration and temperature, determined by a new method

Abstract

A new method of measuring the imbibition pressure of the corneal stroma is described. The tissue is laid on a porous surface wetted with saline and suction is applied until its volume is stable. Changes in the volume of the tissue are determined by surrounding it with oil in a closed container fitted with a capillary tube in which the movements of the oil meniscus can be noted. The method is quick and convenient and gives values of the swelling pressure at different hydrations similar to those found by previous workers. The imbibition pressure was found to drop with time probably as a result of the leaching out of polysaccharide. The pressure is found to drop as the temperature is increased, which is difficult to explain on a theoretical basis and is contrary to the behavior that would be predicted from the theoretical treatments that have been published.