Abstract
Purpose:
With increasing time, epithelial defects (ED) have been shown to develop in virtually all corneas stored in Optisol-GS (OGS), which can predispose post-operatively to persistent epithelial defects, infection, stromal scarring, and graft failure. Life 40C (L4C) is a newer cold-storage corneal preservation medium similar in composition to OGS with the addition of insulin, which has been shown to support epithelial cell functioning in vitro. The purpose of this study was to compare the preservation of donor corneal epithelium during storage in OGS versus in L4C.
Methods:
9 pairs of human corneas were harvested by SightLife (Seattle, WA). One cornea from each pair was stored in OGS (Krolman viewing chamber) and the other stored in L4C (TRANSEND viewing chamber). The corneal epithelia were viewed within the chambers using a backlighting approach, which places a light source directly behind the viewing chamber to elucidate irregularities in the corneal epithelial surface. Slit lamp photography was performed on all corneas upon arrival at the research facility [post-storage day (PSD) 1, 2 or 3], and continued for 14 days. Matched pairs of corneas were stained with fluorescein sodium 0.25% on PSD 15, 16, or 17, and each underwent slit-lamp photography at that time. Photographs were analyzed with ImageJ software, and the percentages of ED area were calculated. Mean differences were compared using the student t-test.
Results:
Mean time from death to preservation was 392.2 ± 97.6 minutes. 2 of 9 (22.2%) OGS and 1 of 9 (11.1%) L4C corneas already had an ED upon first inspection. Of the corneas without initial ED’s, 6 of 7 (85.7%) stored in OGS and 5 of 8 (62.5%) stored in L4C developed an ED by the end of the assessment period. New ED’s occurred as early as PSD 6 in both groups. At PSD 4, 8, and 12, there were no statistical differences in percent change in area of ED between the two groups. Mean change in percent area of ED in the OGS and L4C groups at the end of the observation period were 4.26 ± 6.60 and 2.11 ± 2.55, respectively. (p=0.38).
Conclusions:
OGS and L4C storage media do not significantly differ in their abilities to preserve the corneal epithelium donor tissue for up to 17 days. The majority of corneas stored in either of the two cold-storage media developed ED’s within the 14-day observation period.