[Effects of sutures on rat corneas]

Cellular infiltration of the suture line was studied immunohistologically after rat corneas were sutured with various types of suture materials. The suture line was invaded by helper/inducer T lymphocytes, cytotoxic/suppressor T lymphocytes, and Ia-antigen-positive cells. Among the invading cells, Ia-antigen-positive cells were the most prominent over an extended period of time from immediately after suture placement. The helper/inducer T lymphocytes consisted predominantly of cytotoxic/suppressor T lymphocytes. The 9-0 silk suture produced a higher degree of cellular infiltration than the 10-0 nylon suture or the 10-0 prolene suture. There was no marked difference in the infiltration produced by the 10-0 nylon and 10-0 prolene sutures. After the sutures were removed, the cellular infiltration appreciably decreased. More marked invasion occurred with interrupted sutures than after the inter-lamellar insertion of suture material. These findings indicate that suture materials on the cornea promote infiltration of immunocompetent cells and that mechanical stimulation of the suture notch enhances such cellular response, which may be involved in graft rejection of the corneal transplantation.