Factors influencing the health and longevity of donor corneal endothelial cells

Abstract

Purpose : Although a decrease of corneal endothelial cell (CEC) density is usually observed after corneal transplantation, a high CEC density is retained in some cases, even after 5-years postoperative. Similarly, although the density of cultured human CECs (HCECs) is known to decrease due to passaging, the CECs from some donor eyes reveal a high CEC density even at passage 5 (P5). Thus, the purpose of this present study was to evaluate which donor-associated biological factors specifically correlate with the healthiness and longevity of cultured HCECs.

Methods : HCECs were isolated from the corneal tissue of residual cornea rims post transplantation of the donor corneal graft, and then cultured according to the published protocol. The isolated HCECs were then passaged at a density of 800 cells/mm² to P5, unless the cells could not be passaged due to low CEC density at confluence. CEC density at confluence and the content of matured CECs (CD166⁺CD44^neg~low) (mCEC-ratio) were analyzed at every passage, and the subsequent data was then used to evaluate the correlation with donor age, CEC density, and death-to-preservation time.

Results : The CECs obtained from 30 of 112 donor eyes were successfully cultured at P5. Nine cases exhibited no, or less, loss of CEC density and had over 2,000 cells/mm² at P5. Although these findings appear to be similar to the frequency and percentage of CEC density loss post corneal transplantation, none of the donor-tissue factors listed above correlated with the density of the cultured HCECs and the mCEC-ratio.

Conclusions : Although extensive statistical methods need to be further examined, the findings in this study suggest that the healthiness and longevity of cultured HCECs is controlled by biological factors that are currently unknown.

This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.