Efferent Limb Protection of Corneal Allografts from Immune Rejection

¹ Department of Ophthalmology, Washington University School of Medicine, St. Louis, Mo., and the University of Florida College of Medicine, Gainesville, Fla

Twenty-six rabbits with clear 6.5 mm. penetrating corneal allografts had skin grafts from the same donor eight weeks later. Ten animals rejected their corneas within 16 days. Two and one-half weeks after skin grafting eight of the remaining 16 rabbits had 5.5 mm. corneal buttons excised and resutured within the first graft. These grafts were all rejected 23 to 26 days after skin grafting. Of the eight grafts which were not excised, four remained clear and four were rejected 27 to 50 days after skin grafting. Without intervening skin grafts, all 10 re-excised corneal allografts remained clear. These results indicate that when afferent immune protection is short-circuited by sensitization with skin grafts some corneal grafts are protected from the efferent immune arc by corneal anatomy. When this anatomy is interrupted, efferent protection is abrogated, resulting in an increased graft rejection rate and decreased graft survival.

Key Words: keratoplasty • corneal transplant • immune rejection • efferent limb • graft rejection

Submitted on October 29, 1973