**5. Donor material**

Criteria for the selection of donor corneas are stringent, except in cases of large perforation when access to tissue of optimal quality is not possible. Corneal tissue of excellent grade offers the following advantages:

**5.1**. Healthy tissue with intact epithelium minimizes the risk of re infection in the graft and use of healthy endothelium is critical for the survival of the graft.

**5.2.** Compact and clear tissue helps in monitoring anterior chamber reaction during the immediate postoperative period.

Yao et al. 2003. If fresh donor tissue is not available, the use of cryopreserved tissue and donor corneas preserved in pure glycerin or water-free calcium chloride are effective substitutes in therapeutic keratoplasty to control severe fungal corneal infection and preserve the global integrity.
