Corneal temperature reversal after storage in Chen Medium compared with Optisol GS

Purpose. To compare corneal endothelial cell function by measuring corneal thickness during temperature reversal between corneas stored in two differe nt storage media, Optisol GS and Chen Medium (CM). Methods. Twenty paired c orneas from 10 human donors were randomly assigned for storage at 4 degrees C in Optisol GS (10 corneas) or CM (10 corneas). The storage media were mas ked, and measurements were done in a masked fashion. After storage for 48 h ours, corneal thickness was measured by ultrasonic pachymetry at 2-hour int ervals for 12 hours, during which time the corneas were perfused with BSS ( balanced salt solution) Plus at 37 degreesC. Scanning electron microscopy o f two pairs of corneas from two donors was performed to assess ultrastructu ral change after 12 hours of warming. Results. Corneal thickness decreased during the first 4 hours of the warming period and then increased during th e 6- to 12-hour warming period. These changes in corneal thickness over tim e were similar for the two storage media (p = 0.212). Scanning electron mic roscopy showed greater amounts of endothelial cell disruption in Optisol GS -stored corneas than those stored in CM after 12 hours of warming and perfu sion. Conclusions. The endothelial pump of corneas stored in CM appear to b e as well-preserved as those stored in Optisol GS, although greater endothe lial disruption may be present with Optisol GS by scanning electron microsc opy. Further studies are required to compare the clinical effectiveness of these two media.