Effect of Cortisone on the Permeability of the Blood-Aqueous Barrier to Fluorescein

THE unsatisfactory state of our knowledge regarding the effect of cortisone on capillary permeability has been discussed in a previous paper (Duke-Elder and Ashton, 1951). It was there noted that Leopold and others (1951), injecting fluorescein intravenously in rabbits and estimating its concentration in the aqueous humour, observed no delay in the appearance of the dye in the anterior chambers of cortisone-treated animals in comparison with normal controls. From this it may be concluded that cortisone has no effect on the permeability of the capillaries in the normal eye, for molecules of the size of fluorescein. We have confirmed these negative findings by the use of the same method with a slightly modified technique. In our experiments an intravenous injection of 0.05 ml. 10 per cent. fluorescein was given, and cortisone was injected both intramuscularly (0.5 ml. of 25 mg./ml. solution) and sub- conjunctivally (0.25 ml. of 25 mg./ml. solution).