The Effect of Intravenous Infusion of Hypertonic Saline on the Intra-Ocular Pressure

Abstract

Cats, under nembutal anaesthesia, were given a continuous intraven. drip of 4.5% NaCl. This caused a slow decline in intra-ocular pressure of 2-12 mm. Hg and then the pressure became stabilized. During the infusion the concn. of Na in the blood gradually rose and at the end of the expt. it was in excess in the blood as compared with the aqueous. Normally the intra-ocular pressure is the balance struck between the inward and outwards flows of fluid within the eyes. When the outward flow is artificially increased, as in the above expt., there must be a compensatory mechanism to maintain the intra-ocular pressure. Clinical observation of the aqueous veins during hypertonic saline injn. did not reveal any decrease in the normal drainage of fluid from the eye. An increased rate of formation of fluid is suggested but it has not yet been proved.