Biobanking of Dehydrated Human Donor Corneal Stroma to Increase the Supply of Anterior Lamellar Grafts

Abstract

Purpose: To investigate the effect of dehydration on human donor corneal stroma for biobanking. Methods: Epithelium and endothelium of research-grade human donor corneas (n = 12) were scraped off, leaving a bare stroma with attached sclera. The tissues were placed in a large Petri dish prefilled with silica gel in the periphery and stored at room temperature for 14 days. At the end of preservation, the tissues were rehydrated by being submerged in phosphate-buffered saline for 15 minutes. Transparency (using a custom-built device) and thickness (using optical coherence tomography) measurements were recorded before dehydration, after dehydration, and after rehydration of the tissues. Periodic acid-Schiff and alpha-smooth muscle actin (a-SMA) staining before dehydration and after rehydration were performed to determine the presence of keratocytes and expression of a-SMA. Tensile stress-strain before dehydration and after rehydration was performed to evaluate the biomechanical properties. Results: No difference in corneal transparency before dehydration (69.57 6 6.41%) and after rehydration (67.37 6 2.82%), P = 0.36, was observed. The corneas were more compact after dehydration. A significant change in thickness between before dehydration (625.8 6 75.58 mm) and after rehydration (563.6 6 15.77 mm) stage, P = 0.03, was noticed. The thickness was reduced to 147.6 6 3.71 mm when dehydrated. Periodic acid-Schiff staining showed presence of stromal keratocytes and a-SMA protein expressed in control, dehydrated, and rehydrated corneas. There was no significant difference in the stiffness between control (27.86 6 11.65 MPa) and rehydrated corneas (31.46 6 11.41 MPa). Conclusions: Human donor corneal stroma can be biobanked for up to 2 weeks in a dehydrated condition without losing their molecular or biomechanical properties after rehydration.

Deep anterior lamellar keratoplasty for keratoconus

“…[ 78 79 ] Silica gel dehydration allows preservation of donor corneal stroma with maintenance of thickness, transparency, and biomechanical properties after rehydration. [ 80 ] The Veneto Eye Bank Foundation is storing and distributing dehydrated corneas for possible use in DALK. A randomized controlled trial comparing the outcomes of DALK using dehydrated versus standard organ culture stored donor corneas is currently ongoing in our center (NCT04430244).…”

Cornea donation process and tissue quality for transplantation

“…The current pandemic context of SARS-CoV-2 worsened the high demand for people on the waiting list for corneal transplantation. This scenario emphasized the discussion and search for alternative and safe methods of using corneas without wasting low-quality tissues, such as dehydration techniques of the corneal stroma for a long time without compromising the tissue for transplants of the anterior portion of the cornea or tectonics; the use of peripheral endothelial cells with proliferative potential in cell culture to ensure a substantial increase in the donor endothelial cell pool for regenerative treatments; and the adoption of lamellar techniques for dividing the donor cornea into multiple grafts for multiple recipients [28][29][30][31].…”

Long-Term Outcome of Same-Day Split Corneal Transplantation in Hong Kong

“…2 We believe that the evolution toward split transplantation, long-term biobanking, and eye bank-prepared grafts must be embraced and led by the clinician. [2][3][4][5][6] Kunal A. Gadhvi…”