Abstract
Purpose :
Our lab BiiGC patented an Active Storage Machine (ASM), also called bioreactor for long-term eye banking (in process of industrialization). By restoring intraocular pressure and medium renewal, it maintains corneas' viability over 1-month storage, without deswelling step contrary to organ-culture (OC): in a previous work we showed that 1.6 times more corneas were suitable for graft in ASM than in OC. Besides, tissue quality controls are possible at any time without deconditioning corneas. Aim: To assess if ASM enables to extend storage up to 3 months.
Methods :
12 pairs of corneas with initial endothelial cell density (ECD) >2000 cells/mm2 and <10% difference between both corneas randomly stored with same batch number of commercial medium CorneaMax (Eurobio): one in ASM (21mmHg, 2.6μL/min of medium renewal), the other in OC (100mL of medium renewed every 3 weeks). Primary endpoint: ECD monitored by non-invasive specular microscopy in ASM at D2, M1, M2, M3 and by transmitted light microscopy in OC at D2, M3. Corneas were defined as suitable for graft if ECD remained >2000 cells/mm2, for emergency if ECD remained >1600 cells/mm2. Secondary endpoints: transparency (transparometer), central corneal thickness (SD-OCT), microbiological tests. At M3 (end of storage) pancorneal viable ECD (Hoechst/Ethidium/Calcein), histology, ECs structure/functions (immunostaining, western blot).
Results :
At D2, ECD in ASM versus (vs) OC: 2718±295 vs 2779±396 cells/mm2 (p=0.250).
At M1 in ASM: 2331±259 cells/mm2 with 11/12 corneas suitable for graft and 1/12 for emergency.
At M2 in ASM: 1897±208 cells/mm2 with 5/12 corneas suitable for graft and 6/12 for emergency.
At M3, ECD in ASM vs OC: 1840±216 vs 1479±237 cells/mm2 (p<0.001), with 4/12 corneas suitable for graft and 7/12 for emergency in ASM vs respectively 0/12 and 4/12 in OC.
No contamination occurred in both groups. Corneas remained thin and transparent all along 3 month-storage in ASM.
At the end of storage, viable ECD was 31% higher in ASM than in OC (p<0.001) ; ECs structure/functions were much more preserved in ASM, in particular with NaKATPase 3 times more expressed than in OC (p=0.005).
Conclusions :
The Active Storage Machine enables to extend corneal storage up to 3 months with unprecedented ECs viability. Moreover, it allows eyebanks to have corneas immediately available with normal or acceptable ECD for graft or emergency situations, thus optimizing grafts’ allocation.
This abstract was presented at the 2019 ARVO Annual Meeting, held in Vancouver, Canada, April 28 - May 2, 2019.