Endothelial assessment of donated tectonic corneas: a viable option for posterior lamellar transplantation.

PURPOSE: Donated corneas are classified as tectonic if there are defects within any layers of the cornea which would prevent a satisfactory visual outcome after transplantation. This study aimed to evaluate whether some tectonic corneas have sufficient endothelial characteristics to allow their use in posterior lamellar keratoplasty, and explored their reclassification for use in this sight-improving procedure.

METHODS: A retrospective review of all corneal tissues preserved by the Sorocaba Eye Bank from January to April of 2014 was performed. All donated corneas classified as tectonic were included. Endothelial tissue was defined as healthy and viable for posterior lamellar keratoplasty if endothelial cell density was ≥2000 cells/mm2. Additional parameters analyzed included Descemet folds and stretch marks, loss of endothelial cells, corneal endothelial polymegathism/ pleomorphism, pseudo-guttata, and reflectivity.

RESULTS: During the study period, 2,847 corneas were preserved, of which 423 (14.85%) were classified as tectonic. Of these, 87 (20.56%) were reported as having endothelial viability and were included in the posterior lamellar keratoplasty group. Average corneal endothelial cell density of this group was 2,471 SD ± 256 cells/mm2 (range 2012-2967 cells/mm2).

CONCLUSION: A significant number of corneas classified as tectonic showed endothelial viability and were included in the posterior lamellar keratoplasty group (20.56%). Despite stromal and/or epithelial alterations, these corneas could have been potentially distributed for posterior lamellar transplantation to improve vision, thus reducing the corneal transplantation waiting period. This study highlights how corneal tissue reclassification could increase the potential amount of corneal tissue available for optical transplantation.