Experiment-Based Validation of Corneal Lenticule Banking in a Health Authority-Licensed Facility

With the expected rise in patients undergoing refractive lenticule extraction worldwide, the number of discarded corneal stromal lenticules will increase. Therefore, establishing a lenticule bank to collect, catalog, process, cryopreserve, and distribute the lenticules (for future therapeutic needs) could be advantageous. In this study, we validated the safety of lenticule banking that involved the collection of human lenticules from our eye clinic, transportation of the lenticules to a Singapore Ministry of Health-licensed lenticule bank, processing, and cryopreservation of the lenticules, which, after 3 months or, a longer term, 12 months, were retrieved and transported to our laboratory for implantation in rabbit corneas. The lenticule collection was approved by the SingHealth Centralised Institutional Review Board (CIRB). Both short-term and long-term cryopreserved lenticules, although not as transparent as fresh lenticules due to an altered collagen fibrillar packing, did not show any sign of rejection and cytotoxicity, and did not induce haze or neovascularization for 16 weeks even when antibiotic and steroidal administration were withdrawn after 8 weeks. The lenticular transparency progressively improved and was mostly clear after 4 weeks, the same period when we observed the stabilization of corneal hydration. We showed that the equalization of the collagen fibrillar packing of the lenticules with that of the host corneal stroma contributed to the lenticular haze clearance. Most importantly, no active wound healing and inflammatory reactions were seen after 16 weeks. Our study suggests that long-term lenticule banking is a feasible approach for the storage of stromal lenticules after refractive surgery. Impact statement Since 2011, close to 3 million refractive lenticule extraction procedures have been performed. The majority of the extracted lenticules are discarded. The lenticules could have been cryopreserved and retrieved at a later date for therapeutic or refractive applications. Therefore, establishing a lenticule bank to collect, catalog, process, cryopreserve, and distribute the lenticules could be advantageous. In this study, we simulated a lenticule banking service in a validated health authority-licensed facility and showed that long-term cryopreservation of the lenticules in the facility was safe and feasible in vivo.