Influx of immunoglobulins from the vascular compartment into a grafted cornea

Purpose. To determine the effect of a fresh corneal wound or a healed corneal scar on the immunodiffusion of immunoglobulins into the cornea. Methods. F344 rats were immunized with human serum albumin (HSA) 1 week before an autologous rotational keratoplasty of the right cornea or 1 year after an autograft was performed. One group of rats also was treated with gentamicin-dexamethasone ointment in the grafted eye for 1 week after transplantation to reduce the postsurgical inflammatory signs. A serum sample was drawn every week and booster injections with HSA were given after 2 and 3 weeks. At various times after immunization, groups of rats were killed, blood and aqueous humor samples were taken, and the corneas of both eyes were removed. The corneas were divided into the graft or a 3-mm central button and the peripheral rim and weighed. The anti-HSA titer was determined in serum, aqueous humor, and both parts of the corneas. Results. Up to 5 weeks after transplantation, the grafted corneas contained more anti-HSA immunoglobulins than did the control eye. One year postgrafting, no difference was seen. In the first weeks after keratoplasty, influx of anti- HSA from the peripheral into the central cornea was, however, neither obstructed nor enhanced. Conclusions. Surgical trauma in itself causes increased influx of anti-HSA immunoglobulins into the cornea. Within the cornea, a wound or a scar does not appear to be a barrier for centripetal immunoglobulin diffusion.