Abstract
Purpose:
Corneal (lymph)angiogenesis is a prime risk-factors for immune rejection after transplantation. We recently presented a technique to regress pre-existing pathological corneal lymphatic vessels prior to transplantation by photodynamic therapy (PDT). Here we analysed the effect of photodynamic regression of corneal lymphatic vessels on subsequent corneal graft survival.
Methods:
The murine model of high-risk keratoplasty was used by placing three interrupted 11-0 sutures into the corneal stroma of BALB/c mice and leaving them in place for 2 weeks. Thereafter, the treatment group received an intrastromal injection of verteporfin (controls: PBS) followed by PDT. Subsequently, one, two or three weeks later penetrating keratoplasty was performed with C57BL/6 donors (all mice female). Postoperative survival of the grafts was analyzed over 8 weeks subsequently.
Results:
Performing PK in high risk eyes two or three weeks after corneal stromal PDT resulted in significantly higher graft survival rates (p<0.005 and p<0.05, respectively; n=8). When performing the corneal transplantation one week after corneal stromal PDT, no significant difference in graft survival could be detected (p>0.05; n=7).
Conclusions:
This study for the first time shows that PDT after corneal intrastromal verteporfin injection is a new “preconditioning strategy” to reduce pre-existing corneal lymphatic vessels prior to transplantation and thereby to prevent allograft rejection in the high-risk situation.
Keywords: 555 immunomodulation/immunoregulation •
741 transplantation •
479 cornea: clinical science