Permeability of the corneal endothelium to fluorescein--a follow-up of keratoplasty cases.

The permeability of the corneal graft endothelium to fluorescein was determined, by the oral administration method, in 47 eyes with penetrating keratoplasty. The endothelial permeability was expressed as the transfer coefficient of the dye between the anterior chamber and the cornea. In the early postoperative period, an increase in the aqueous protein was noted and a correction was made for fluorescein binding to aqueous protein. The measurements of the graft thickness and morphometry of the endothelial cells by specular microscopy were also carried out concurrently. The transfer coefficient was high in the early postoperative period, and was reduced by time. Similarly the graft was thick in the early postoperative period but it thinned to a normal level over a period of several months. A significant correlation was found between the transfer coefficient and the corneal thickness. The mean cell size of the graft endothelium was significantly greater than that of the normal cornea. The mean cell size and the postoperative period were correlated using the present data and those reported by Sato previously. A significant positive correlation was found, indicating progressive enlargement of the graft endothelial cells over a long period of time. The mean cell size was not significantly correlated with the transfer coefficient nor with the graft thickness.