Abstract
Purpose:
Corneal storage conditions vary widely between continents: whereas short-term storage is the method of choice in the United States, long-term organ culture is preferred by European eye banks. We have previously shown that graft adhesion is affected by the culture method with short-term cultured grafts requiring significantly higher number of rebubbling procedures (Laaser et al., Am J Ophthalmol, 2011). In order to evaluate the underlying mechanism we investigated the effect of donor tissue culture conditions on the degree of spontaneous scrolling of the graft.
Methods:
Retrospective analysis of 100 consecutive grafts prepared for DMEK surgery was performed. Based on the culture conditions, grafts were divided into two groups. To create age matched groups patients older than 70 years had to be excluded from this study because the average age in the cold storage group was relatively young. 34 grafts fulfilled the inclusion criteria and were enrolled in this study. 13 grafts were prepared from short-term cultured corneoscleral buttons (STC, storage: Optisol-GS at 4°C, Bausch & Lomb, Irvine, CA, USA) and 21 grafts were prepared from organ-cultured corneoscleral buttons (OC, storage: Dulbecco's Modified Eagle's Medium at 34°C, Biochrom, Berlin, Germany). The degree of the scrolling of the graft was measured by comparing the diameter of the scroll after detachment from the corneoscleral button with the lumen of the injector cartridge (Ø 3.6 mm, Medicel, Wolfhalden, Switzerland).
Results:
There was no statistically significant difference concerning mean donor endothelial cell count (STC: 2569 ± 216 cells/mm2; OC: 2548 ± 159 cells/mm2; p>0.05) and mean donor age (STC: 61 ± 5 years; OC: 64 ± 5 years, p>0.05) between both groups. Mean storage duration was significantly shorter in the STC group (7 ± 1.2 days) than in the OC group (12 ± 3.6 days; p<0.01). Grafts of the STC group showed no significant difference concerning the degree of spontaneous scrolling compared to grafts of the OC group (p>0.05).
Conclusions:
Our results suggest that donor tissue culture conditions have no effect on the scroll formation. Previously described differences in graft adhesion between different culture modalities might therefore be due to e.g. biomechanical/biochemical properties of Descemet's membrane.