A clinical method for assessment of endothelial viability in donor corneae.

IT is now well-established that endothelial viability of the donor cornea is essential for successful penetrating keratoplasty (Kaufman, Capella, and Robbins, 1966; Stocker, Eiring, Georgiade, and Georgiade, 1959). Unfortunately all the current methods of assessment render the donor eye unsuitable for a subsequent penetrating graft. These include: (1) Morphological studies of the endothelium of the intact cornea following: (a) Histochemical staining of the cellular enzymes (Robbins, Capella, and Kaufman, 1965). (b) Staining with a vital stain such as trypan blue (Stocker, King, Lucas, and Georgiade, 1966). (c) Staining with nuclear stains. (d) Staining with silver nitrate (Wilcox, Wood, Oh, Everett, and Evans, 1958). (2) Tissue-culture techniques, including embryonation of thin strips of endothelium placed on a chorio-allantoic membrane of a 9-day-old chick embryo and incubated for 48 hours to remove dead endothelial cells and preserve the living cells (Ocampo and Salceda, 1966). (3) Oxygen uptake of the isolated endothelium using a semi-micro respirometer (Leigh and Ridge, 1957). At present donor eyes have become more plentiful in London; thus some attempt should be made at greater selectivity of material for penetrating grafts in the hope of reducing the incidence of graft failures. In this study we have examined with the slit lamp the posterior surface of the cornea of 400 eyes, and have described changes in the endothelium which indicate some measure of endothelial non-function as gauged by vital staining. All the eyes were collected by the Westminster-Moorfields Eye Bank and were examined as soon after death as possible. The eyes were obtained from patients ranging in age from 24 to 85. They were enucleated using a sterile technique, with the minimum of trauma, and were placed in small, dry, air-tight sterile jars for transportation, surrounded by ice in the large polystyrene box (described by Mueller, O'Neill, and Trevor-Roper, 1965) which we have found to be the most satisfactory method of transportation. The eyes were examined at varying periods after death, ranging from 3 to 48 hours, and the following factors were carefully noted: (1) Age of the deceased. (2) Cause of death. (3) Temperature at which the body was refrigerated. (4) Temperature at which the enucleated eyes were stored.