The pattern of corneal graft rejection

Area of Science:

• Ophthalmology
• Transplantation immunology

Background:

• Penetrating keratoplasty (PKP) is a common corneal transplant procedure.
• Graft rejection remains a significant complication, impacting visual outcomes.
• Understanding rejection patterns is crucial for improving graft survival.

Purpose of the Study:

• To analyze the incidence and location of initial graft rejection episodes in penetrating keratoplasty.
• To investigate potential factors influencing the site of corneal graft rejection.

Main Methods:

• Retrospective analysis of 160 consecutive penetrating keratoplasty cases performed between 1981 and 1987.
• Detailed examination of the site of initial graft rejection episodes.
• Exclusion of grafts with pre-existing vascularization or loose sutures to isolate rejection patterns.

Main Results:

• The overall incidence of homograft rejection was 34% (54 out of 160 grafts).
• After excluding specific cases, initial rejection predominantly occurred at the inferior limbus (17 cases) compared to the superior limbus (1 case).
• Diffuse corneal edema was observed in 8 cases at initial presentation.

Conclusions:

• A higher incidence of penetrating keratoplasty graft rejection occurs inferiorly.
• Tear film factors may play a role in promoting rejection at the inferior graft-host interface.
• Further research into tear film components is warranted to mitigate rejection risk.