[Microbiological safety and endothelial quality control during preservation of corneal grafts at +31 degree C]

Over a 10-month-period, 59 corneas were organ-cultured at + 31 degrees C and 7 were preserved at + 4 degrees C. Among the 59 organ-cultured corneas, 41% (24) were grafted and 25% (15) developed an infection during preservation. At the time of surgery, preservation medium and scleral rim were tested for microbiology. Infection during preservation was bacterial (80%, 12/15) and fungal (20%, 3/12). Scleral rims were sterile in 96% (24/25) of the grafted corneas preserved at + 31 degrees C but 34% (2/6) at + 4 degrees C (p < 0.01). Preservation media were sterile in 100% (24/24) of organ-cultures at + 31 degrees C but in 83% cases (5/6) of preservations at + 4 degrees C (NS). The percentage of endothelial dead cells increased with postmortem enucleation delay (r = 0.43; p = 0.03). The average endothelial cell loss during organ-culture was 11.2% (+/- 10.4). It correlated with endothelial density (r = 0.42; p = 0.04) and with percentage of endothelial dead cells (r = 0.43; p = 0.04) after enucleation. Organ-cultured at + 31 degrees C was able to assess graft sterility in almost 100% of the cases but corneas are lost due to infection. Graft sterility is not usually possible with preservation at + 4 degrees C.