Impact of Transportation on the Suitability of Cryopreserved Corneal Lenticule for Implantation.

Abstract

Corneal lenticules can be deposited and retrieved for vision-restoring surgeries. Extended transportation logistical delays from the lenticule bank to the clinic could be a concern. To investigate this, corneal lenticules were cryopreserved at a Ministry of Health of Singapore-licensed lenticule bank for 1 year and were then transported at 4 °C. The transparency was measured daily until significant degradation was notable, compared to fresh lenticules from donor corneas (n = 3). The molecular and ultrastructural integrity of lenticules after 1 day in transport (n = 3) and on the day of transparency deterioration (n = 3) was evaluated by histochemistry and transmission electron microscopy (TEM). In addition, 9 rabbits were implanted with these lenticules to assess the difference in postoperative outcomes by corneal imaging, immunofluorescence staining, and TEM. Lenticules showed a significant transparency reduction after 6 days in transit (p = 0.002). The change was not caused by collagen, glycosaminoglycan, and glycoprotein alterations but by a significantly greater shift in the distribution of the interfibrillar distance (IFD) (Z = 4.419; p < 0.001) and fibrillar diameter (FD) (Z = 6.435; p < 0.001). When implanted, day 6 lenticules exhibited greater light reflectivity and slower recovery of clarity compared to fresher lenticules, despite a combination of corneal imaging and immunofluorescence staining showing no fibrosis, inflammation, or vascularization in either group. With TEM, the discrepancy was revealed due to the difference in the restoration of IFD and FD distribution. In conclusion, banked lenticules can maintain transparency for up to 5 days of transportation at 4 °C. Further delays compromise their ultrastructural integrity and postoperative clarity, emphasizing the need to factor in transportation in lenticule banking logistics.