VisionFirst CEBT Practice Test

In epikeratoplasty, the donor tissue is placed on the front surface of the recipient’s cornea, so the part of the donor that governs surface clarity is what matters most for the graft’s success. Endothelial health of the donor tissue is less critical here because the endothelium sits on the inner side and does not participate in forming the new front surface. Therefore, tissue that has a local disease affecting the endothelium can still be used, since that endothelial issue won’t impair the optical surface created by the graft. In contrast, disease limited to the cornea itself (epithelium or stroma) would degrade transparency and healing, making such tissue unsuitable. The question about death-to-preservation time concerns logistics rather than tissue quality, so it’s not the deciding factor for this contraindication.