Femtosecond Laser–Assisted Allogenic Lenticule Implantation for Corneal Ectasia After LASIK: A 3-Year In Vivo Confocal Microscopic Investigation

Abstract

PURPOSE: To investigate morphological changes in the cornea and the implanted lenticule in patients with corneal ectasia after laser in situ keratomileusis (LASIK) and implantation using a lenticule from small incision lenticule extraction (SMILE). METHODS: Eight eyes of 8 patients with ectasia after LASIK from 2015 to 2018 at the Eye and ENT Hospital of Fudan Unversity were analyzed. For recipient eyes, lenticules were transferred with a mean cryopreserved time of 20 ± 21 days extracted from SMILE donors to the exposed stromal bed after lifting the flaps and the flap was repositioned. Uncorrected and corrected distance visual acuity, manifest refraction, and corneal topography were performed. Patients were followed up for 3 years. Changes in lenticules and recipient corneas were analyzed using in vivo confocal microscopy. RESULTS: Activated keratocytes in the anterior and posterior stroma were observed near the lenticule at the first 6 months. Elongated, deformed keratocyte nuclei were found in the implanted lenticules in postoperative year 1. The anterior and posterior interfaces showed an absence or decrease of keratocytes and the presence of small particles of varying brightness. Nerve fibers in the implanted lenticules were detected in one case. No obvious difference was detected between cryopreserved and fresh lenticules. CONCLUSIONS: The preliminary findings suggest that recipient keratocytes repopulate the lenticules and the keratocytes in lenticules gradually return to their normal morphology. [ J Refract Surg . 2020;36(11):714–722.]

Comparison of the Effects of Temperature and Dehydration Mode on Glycerin-Based Approaches to SMILE-Derived Lenticule Preservation

“…The reimplantation of cryopreserved lenticules has been shown to be both safe and effective as a means of treating a range of ocular diseases, 11 , 12 and these preserved lenticules did not exhibit any apparent differences in subsequent wound healing when compared with fresh lenticules. 13 Glycerol is commonly used for prolonged preservation of human tissues and organs, including red blood cells, skin, and bone tissue. 14 – 16 Different glycerol-based cryopreservation solutions, however, exhibit distinctive properties.…”

Effect of SMILE-derived decellularized lenticules as an adhesion barrier in a rabbit model of glaucoma filtration surgery

“…The increasing popularity of this has made it easier to obtain SMILE-derived lenticules. The decellularized lenticule is a thin stromal layer with low immunogenicity and good biocompatibility, making it an excellent candidate for corneal stromal regeneration [21,22]. We have previously shown that decellularized lenticules could safely and effectively repair damage to the anterior cornea in rabbits [13].…”

Update of Research Progress on Small Incision Lenticule Extraction (SMILE) Lenticule Reuse

“…Then, they included 7 similar patients treated with the same surgical method and followed up for three years, and all patients had satisfactory outcomes and no significant complications during the follow-up. 63…”