Risk Evaluation of Human Corneal Stromal Lenticules From SMILE for Reuse

PURPOSE: To investigate the pathogenicity and immunogenicity of human corneal stromal lenticules from small incision lenticule extraction (SMILE). METHODS: Serological testing was completed prior to sample collection to rule out infectious diseases. Pathogens herpes simplex viruses (HSV) type 1 and type 2 were screened for by real-time fluorescent quantitative polymerase chain reaction, and bacteria, fungi, and Acanthamoeba from 128 lenticules of 64 patients were cultured. A total of 132 lenticules from 93 patients were randomly assigned to the fresh group, -78 °C anhydrous glycerol preservation group (glycerol group), and 0.1% sodium dodecyl sulfate decellularization group (SDS group) in pairs and detected by immunohistochemistry, Western blot, transmission electron microscopy, transmittance, and nanoindentation. RESULTS: The fresh lenticules were all negative for HSV-1, HSV-2, bacteria, fungi, and Acanthamoeba. HLA-I A/B/C and HLA-II DR antigens were all expressed in fresh lenticules but were clearly reduced after preservation at -78 °C in anhydrous glycerol or decellularization in 0.1% SDS. The collagen fibers of the lenticules in the fresh group were regularly arranged, and the keratocytes were intact. The fibers in the glycerol group were regularly arranged, and the integrity of keratocytes was destroyed. The fibers in the SDS group were disordered and had no cellular structure. The transmittance and Young's modulus were highest in the fresh group, lower in the glycerol group, and lowest in the SDS group. CONCLUSIONS: Risk of infection is low, but risk of rejection exists on the reuse of fresh human corneal stromal lenticules from SMILE. Anhydrous glycerol preservation at -78 °C is an ideal method for reducing antigens without damaging the structure and function of lenticules. [J Refract Surg. 2021;37(1):32-40.].