Corneal Hemangiogenesis And Lymphangiogenesis Immediately Following Penetrating Keratoplasty Are Triggered By Surgery Rather Than Alloimmunity

Abstract

Abstract: : Purpose: The development of new blood and lymph vessels in the graft bed following penetrating keratoplasty (PK) is known to be a risk factor for graft failure. We wished to determine the extent to which neoangiogenesis in this setting arises from the recipient alloimmune response, as opposed to the impact of surgery and wound healing. Methods: Orthotopic corneal transplants were performed with C57BL/6 donors, and BALB/c and CB17 SCID recipients. At three and 7 days post transplantation, flat mounts were prepared from graft–containing corneas and analyzed morphometrically for the presence of blood and lymph vessels using double immunofluorescence with CD31 as a panendothelial–marker and LYVE–1 as a lymphatic vascular endothelial cell–specific marker. Results: Blood and lymph vessels emerged simultaneously from limbal vessels at 3 days post–transplant aion in graft–bearing corneas of both BALB/c and immune–deficient recipients. Moreover, blood and lymph vessels types penetrated the graft–host interface by 7 days in both recipient types. Conclusions: Since the neoangiogenesis and lynphangiogenesis that arises in graft beds during the first week post–PK is equally robust in normal and immune–deficient recipients, surgical trauma, rather than alloimmunity, is the primary source of this risk factor for graft failure.

Keywords: neovascularization • transplantation • vascular cells